Emilio Mignone, his battered leather briefcase filled with dossiers of the tortured, the missing and the dead, makes his way through the corridors and reception rooms of the Sheraton Hotel here, talking of human rights to those who will listen.

His gain slowed by age, illness and personal tragedy, Mignone metaphorically carries the weight of his daughter's disappearance and those of 6,000 to 15,000 other Argentines on his hunched shoulders.

He hardly ever smiles.

Juan Ferreira, whose father, Wilson Ferreira Aldunate, was one of Uruguay's most respected political leaders before the 1973 military takeover that sent both father and son into exile, has been here for 10 days representing the National Council of Churches.

Things had gone smoothly enough until yesterday, when Col. Juan Antonio Bonifasino, Uruguay's military attache in Bolivia, suddenly lost his temper, pushing and punching Ferreira, challenging him to step outside the site of the Organization of American States General Assembly to fight.

Indeed, today, the OAS nations approved 19-2 a far-reaching resolution on human rights that several years ago would not even have been considered for debate. In all, four resolutions were approved, addressing conditions in specific nations despite the discomfort of those countries' delegations seated in the room.

Mignone and Ferreira are two of about half a dozen human rights "lobbyists" here for the assembly, which in recent years has become an important forum for speaking out against the abuse of persons for their political beliefs.

The other lobbyists represent such organizations as the Washington Office on Latin America, an American church-related group, and Amnesty International.

The human rights lobby, armed with moral indignation and this year's Inter-American Human Rights Commission report -- which found that although there were some "encouraging signs . . . there were no significant changes" in the past pattern of widespread violations -- has been instrumental in seeing that the issue did not lose its urgency or importance at this assembly.

Human rights made fewer headlines this year, according to several observers, because the subject is no longer new or exotic to the OAS member states.

"There has been less rhetoric and more work," said Ferreira shortly before a working committee approved the resolution, toughest in OAS history, that will be adopted by the assembly in the closing session expected on Wednesday.

"Human rights is being incorporated into the OAS. Almost every delegation has a human rights officer this year, which is absolutely new," Ferreira said. "This is far more important than rhetoric."

The central resolution was the subject of heavy behind-the-scenes negotiations in an effort to preserve the OAS tradition of passing resolutions by consensus.

The head of Uruguay's delegation, Carlos Giabruno, walked out of one working session, which led to Col. Bonifasino's attack on Ferreira, and ultimately cast his country's vote against the document because it called on Uruguay to honor its pledge to hold elections in 1981.

Paraguay also voted "no," while Argentina, Guatemala, Chile, Brazil and St. Lucia abstained. Honduras was not present for the vote, which resulted in 19 countries, including the United States, voting in favor.

The resolution registered OAS opposition to torture and disappearances, which the document calls "an affront to the hemisphere's conscience." It also commended Panama for inviting the OAS's rights commission to revisit the country to observe the measures that the government there says have been taken to clear up earlier abuses.

The resolution also calls on Chile to take the steps necessary to "secure the full observation of human rights." It asks Paraguay to respect human rights, allow the commission to make an on-site visit and to lift the state of siege that has been in effect for more than 25 years.

Uruguay, in addition to being called upon to hold its promised elections in 1981, is asked to respect the rights to its citizens.

Another resolution congratulates the new promising to respect human rights and directs the Human Rights Commission to continue monitoring the situation.

Still another resolution urged governments, such as those in Chile and Argentina, not to implement laws that would "interfere with investigations of the disappeared." A final rights resolution urges governments not to persecute religious groups, particularly the Jehovah's Witnesses, which have had serious problems in Argentina and Paraguay.

For the handful of rights lobbyists, the four adopted resolutions were a significant advance in establishing the OAS' competence and determination to improve human rights in the Western Hemisphere -- which, according to Olivier Guignabaudet of Amnesty International includes several of the world's most serious human rights violators.

Both Guignabaudet and Heather Foote of the Washington Office of Latin American said their work would be made easier if they were allowed to speak directly before the OAS human rights working committee and to pass out documents through official OAS channels, a suggestion so far rejected.

As a result, the lobbyists plied the halls in search of friends to sponsor their resolutions before the General Assembly, or include information they thought important.

This year, Guignabaudet, Foote and Mignone said they found Grenada, Ecuador, Surinam, Jamaica and Nicaragua to be especially cooperative and outspoken on their behalf.

Only Juan Ferreira found trouble -- with the delegation from his nativee Uruguay.