In ensuing years, the military dictatorship that ran Brazil arrested or detained him about 10 times. Police cars passed by his house in São Paulo's industrial suburbs, he said, and officers would make throat-slashing gestures or wave guns at him.
Oliveira's apparent offense: Being a union organizer during an era when the military considered strikes to be tantamount to communist subversion.
"I used to joke that my house was the safest in the neighborhood, with all the police," said Oliveira, now 63. "But it was tough, really scary, like psychological torture."
Worse, he said, local manufacturers refused to hire him for years afterward, vaguely citing his past. Other colleagues met the same fate. "We always suspected the companies were passing information on us to the police," he said. "But we never knew for sure."
Newly uncovered evidence suggests that Oliveira's suspicions were well-founded.
A government-appointed commission investigating abuses during Brazil's 1964-1985 dictatorship has found documents that it says show Rapistan and other companies secretly helped the military identify suspected "subversives" and union activists on their payrolls. Among those named is Oliveira. The official report isn't scheduled to be released until December, but the commission allowed Reuters to review the evidence involving companies as the investigation nears its end.
Foreign and Brazilian companies are cited in the documents, including, most prominently, some of the world's biggest automakers: Volkswagen AG, Ford Motor Co, Toyota Motor Corp and the Mercedes-Benz unit of Daimler AG, among others.
No companies have been accused of any crimes. Whether they collaborated with the dictatorship, and to what extent, are in dispute. Nevertheless, human rights advocates and some of the workers named in the documents say they may pursue civil lawsuits or other legal action as a result of the commission's findings.
Some workers want the companies to pay reparations for lost wages. Others, including those who doubt the commission's findings will be conclusive enough for a court case, say they would be satisfied with an apology.
The commission is tasked with shedding new light on abuses during that era and who was responsible for them. The U.S.-backed dictatorship killed some 300 people and tortured or imprisoned thousands more in what it saw as a fight to stop leftists from turning Brazil into a giant version of Fidel Castro's Cuba.
Rousseff, who is running for re-election in October, has expressed hopes that a fuller historical record will help ensure that Brazil, now a thriving democracy and rising economic power, never repeats that era's mistakes.
Businesses in general benefited from the dictatorship's conservative policies. Academics have long believed that local and multinational companies helped the regime identify employees who were fomenting labor unrest or otherwise posed a supposed threat to stability.
Now, the commission's researchers have discovered evidence that they believe proves such a relationship.
"THE BLACK LIST"
The documents do not provide a complete record of state repression during the dictatorship. Some papers from that period were burned by the military or otherwise vanished; some have been found in the past year in the homes of former officers after they died; others are scattered among state archives.
The commission's most prized discovery to date is a document found in São Paulo state's archives that researchers informally call "the black list."
The typewritten list contains the names and home addresses of some 460 workers from 63 companies in an area of Greater São Paulo that is sometimes called "Brazil's Detroit" because many foreign automakers are based there.
The list dates from the early 1980s. It was put together by the Department of Political and Social Order, or DOPS, a police intelligence agency that existed primarily to monitor and repress leftists. Historians say DOPS detained an undetermined number of people, including President Rousseff, and tortured many of them.
Volkswagen had the most employees on the DOPS list, with 73. Mercedes-Benz was second with 52.
The document does not say what DOPS used the list for, or what criteria were used to select the names. The document also does not indicate how DOPS obtained the information.
Rosa Cardoso, a lawyer who heads the truth commission's subcommittee investigating abuses against blue-collar workers, said the list appears to have been used to monitor labor activists at a time when unions in Greater São Paulo were becoming more assertive in their demands for better wages and working conditions.
The document, or some version of it, may have also been circulated to companies to prevent workers from getting jobs elsewhere once they were fired, she said, based on interviews the commission has conducted.
The list includes so much proprietary information that, Cardoso argues, the data had to have been provided by the companies. More than half the entries on the list include the area of the factory where the workers labored. That information, made in handwritten notes next to the workers' names, is highly specific, denoting either the department's function ("Maintenance") or its internal name ("Sector 4530").
"It's proof that these companies conspired to repress their workers," Cardoso said.
Some scholars caution that it is possible that worker information was obtained by other means - for instance, via union informants, or by the DOPS itself. Asked about these alternative explanations, Cardoso said: "Not in these numbers, with this detail."
Some documents uncovered by the commission more clearly indicate that companies passed information to the military.
Researchers found a two-page letter from São Paulo's civil police force to the DOPS, dated March 9, 1981, regarding David Rumel, then a doctor for the metalworkers' union.
The letter includes Rumel's date of birth and home address but is mostly focused on his leftist past. It notes that he joined the Brazilian Communist Party as a student in 1971 and was imprisoned for five months from 1975 to 1976.
In the letter, the police state the information was "collected by the security service of Volkswagen Brazil."
Rumel's name did not appear on the "black list." Efforts to reach him were unsuccessful.
In response to detailed questions from Reuters about whether it provided information on Rumel and others to the military, Volkswagen Brazil said it has not yet been contacted by the truth commission. Yet, in a development that may be the first of its kind in Brazil, Volkswagen said it would initiate its own probe.
"Without knowledge of the concrete documents we aren't able to give you answers to all your questions," spokesman Renato Acciarto said via email. "But Volkswagen will investigate all indications to get more information about the company and the state institutions during the period of military (rule)."
"Volkswagen will throw light on this matter to get full knowledge" of what happened, he wrote.
She added: "We value our employees and respect their privacy, and would not condone the conduct alleged" by the truth commission.
A spokesman for Mercedes-Benz in Brazil said that the company "does not confirm" giving information to DOPS, and that it "has among its values the protection of the personal information of its employees."
Ford declined to comment. Toyota and Fiat, which now owns Chrysler, said they had no records of potential abuses during that era. "We would like to remind you that we're talking about a period more than 30 years ago," said Erick Boccia, a Toyota spokesman.
A LATHE OPERATOR ON THE LIST
Reuters interviewed 10 people whose names appeared on the "black list." Most reported having been fired by the companies in the early 1980s, around the time the document appeared. Some said they were arrested at least once, sometimes at picket lines. Most reported problems later finding work.
None of the workers said they met with torture or extended imprisonment in the years after the list appeared. That tracks with historians' findings that the military's harshest tactics had largely ceased by the mid-1970s, as armed guerrilla groups diminished in number and more moderate generals gained influence.
Manoel Boni, 59, said he was fired by Mercedes-Benz after participating in a strike in 1980. In ensuing years, he repeatedly applied for positions as a lathe operator at other automakers outside São Paulo, including some factories that had posted openings for such jobs.
The companies didn't hire him. Boni said he depended for extended periods on churches or help from friends. He eventually found work at a small factory near downtown Sao Paulo, some 12 miles (20 km) away.
Upon being shown the list for the first time by Reuters, Boni said: "My God, my God."
"Sector 381," he said, reading aloud the handwritten annotation next to his name. "Yes, that was quality inspection, where I worked."
He paused for a long moment, reading the other names. "Many things make sense now," he finally said.
Oliveira, the former Rapistan employee, had to leave town to find a new job. He didn't give up trying to recruit workers to his old union, though.
"We met at night, under trees, wherever was necessary," he said. He now works at an association for retired metalworkers.
Kanashiro said he once met with a human resources representative from another large foreign automaker in Greater São Paulo. "He told me, 'You're on a list, and you'll never work in the private sector again,'" Kanashiro said.
Not everyone on the list had such bad experiences. Geovaldo Gomes dos Santos, who worked in accident prevention for Volkswagen, said he felt like his bosses were trying to push him out in the early 1980s. He stuck with the job anyway, and finally retired from the company in 2003.
Still, he has vivid memories from the tough years. "If you supported the union, they treated you like a bug," he said. "I'd like to see some justice for what happened to others."
AMNESTY LAW COMPLICATES THINGS
The big question looming over the commission's work is what kind of justice is possible.
Unlike some other South American countries that experienced Cold War-era dictatorships, Brazil until now has never seen a concerted effort to investigate serious abuses.
That's partly because Brazil's military killed far fewer people than its regional peers. Argentina's 1976-1983 regime killed as many as 30,000 - about 100 times Brazil's toll, in a country with roughly one-fifth the population. Prior to handing power back to civilians in 1985, Brazil's military also negotiated a sweeping amnesty law that has to date prevented courts from prosecuting most "political crimes" from the dictatorship era.
As a result, some jurists are guarded about the chances of successful prosecutions.
"In theory, if a company contributed to or benefited from a violation of human rights, it can be held responsible," said Marlon Weichert, a prosecutor and specialist in international human rights law at Brazil's Public Ministry, a judicial body that could prosecute a case based on the commission's findings.
Apprised of the truth commission's work to date, Weichert said via email that the findings were "important," but stressed he would need to see the full evidence before saying whether or precisely how a case against companies would be pursued.
Last year, prosecutors in Argentina filed criminal charges against three former Ford executives who allegedly gave names, home addresses and pictures of workers to Argentine security forces during that country's dictatorship. Some of those workers were jailed and tortured. The three men deny the charges and have pleaded not guilty. The case is making its way through Argentine courts.
Meanwhile, Brazil's truth commission may summon or invite the companies that figure most prominently on the "black list" to give their version of the story in coming weeks, said Sebastião Neto, who is overseeing the research on companies.
"YOU HAVE TO PROVE IT"
Others think the commission is overplaying its hand.
Augusto Portugal, a former Rolls-Royce employee who is on the list, is hoping for reparations from the companies. But he worries that, if the commission solicits their testimony based on inconclusive evidence, it could cause the companies to retreat behind a firewall of silence and lawyers.
Portugal has interviewed some 30 people on the list while writing a post-graduate thesis on the document, and says it isn't completely clear where the information came from. "It's obvious the companies collaborated" with the military, he said. "But you have to prove it."
Also unclear is how actively Rousseff, despite her past, will support any efforts at prosecution. Some in her party wanted to include a "revision" of the 1979 amnesty law in her official re-election platform. That proposal has met resistance from some of her aides, who worry she has her hands full with a stagnant economy and declining popularity.
Others say the public attention given to the truth commission has been its own reward, by awakening a public debate about dictatorship-era crimes.
O Globo, a newspaper that is part of a media empire that championed military rule, issued an editorial last year saying "that support was an error" - prompting speculation that other companies might soon follow suit.
Meanwhile, some on the list take comfort that in the end, they arguably won.
The labor unrest at automakers in Greater São Paulo ended up spreading, weakening the military and leading to a managed transition to democracy in 1985. The union movement, emboldened, created a new political party: The Workers' Party.
One of its founders, labor leader Luiz Inácio Lula da Silva, became Brazil's president in 2003. Rousseff is also a member of the Workers' Party, and Brazil now has some of the world's most generous labor laws.
"Lula always told us that, to really prevail in our battle, we'd need to found a party and try to change society," said Kanashiro, the former Mercedes worker on the list, who is now a Workers' Party official in Brasilia. "We never thought it would happen so fast. But that doesn't change the fact that we want justice for these abuses."