For U.S. Attorney Russell T. Baker Jr., appearing in a courtroom here today was a chance for reminiscence, calling up memories of a momentous day in his career as a federal prosecutor.

For engineer Jerome Wolff, who appeared in the same courtroom, it was a time for memories too, "terrible" ones that he wishes he could put behind him.

Both men were key players in the 1973 drama that led to the unprecedented resignation of a vice president: Spiro T. Agnew, who pleaded no contest to a criminal tax charge and left office when confronted with allegations that he had accepted cash kickbacks first while Maryland governor and then while vice president.

Baker was one of the bright young federal prosecutors in Maryland who built the case against Agnew. Wolff, a one-time Agnew friend and political appointee, was one of Agnew's key accusers.

Now, nearly eight years later, both men were drawn together again -- this time to testify against Agnew in a civil lawsuit initiated by three Maryland taxpayers who are trying to collect for the state more than $200,000 that Agnew and two associates allegedly took in a kickback scheme.

After four years of legal battles, the trial opened today with Baker and Wolff among the first witnesses.

On the stand, Baker recounted how the case against Agnew was painstakingly built with months of investigation, culminating when prosecutors won sworn statements from Wolff and three other Agnew associates. The statements outlined Agnew' alleged role in a system that exchanged lucrative state engineering contracts for cash payments.

Wolff then took the stand to relate portions of his 1973 statement to prosecutors, which outlined how he had split kickbacks with wealthy Baltimore builder I. H. Hammerman II, who allegedly told him that Agnew was getting half of the funds. While Agnew was governor in 1968 and 1969, Wolff was his State Roads Commission chairman and Hammerman was one of his closest friends.

There was nothing in the testimony that had not been previously known or widely believed, but the occasion marked the first time that any of the men who helped topple Agnew from the vice presidency had appeared in court to tell their stories.

Later, outside the courtroom of Anne Arundel County Circuit Court Judge Bruce C. Williams, baker said the opportunity had brought back memories of the Agnew investigation. "Like anything else that turned out well, it's fun to remember," said the poised and smiling Baker.

Although he wouldn't comment on his feelings about the current civil trial, Baker said that Agnew had committed "serious offenses for which anyone else would have gone to jail. But he was able to extort out of [then U.S. Attorney General Elliot] Richardson a very favorable deal by holding the vice presidency hostage." Baker added that he did not want to be critical of Richardson's decision, and said: "In restrospect, I'm not sure he wasn't right."

Wolff, the engineer, whose success had paarlleled Agnew's own rise from Baltimore County politican to the governor's mansion and then the vice presidency, was anything but pleased to be drawn into the Agnew case again. A baldish, ruddy-faced man of 63, Wolff had once been described as a brilliant engineer by colleagues, and had been head of an environmental engineering firm in 1973. But after Agnew's historic plea to a single charge of federal income tax evasion on Oct. 10, 1973, Wolff left that firm and battled for several years to hang on to his engineering license.

Today, he said that business is "lousy. I keep losing jobs because I keep showing up in newspapers in the worst possible light."

He said he felt "terrible" about testifying in court, adding that the Agnew revelations and their aftermath have had "a serious psychological effect on me."

Wolff, along with Agnew and Hammerman, was originally named as a defendant in the taxpayer suit when it was filed in 1976. But Wolff will be dismissed as a defendant in return for his testimony.

Last year the taxpayers, who had been joined in the suit by the state attorney general, won an agreement from Hammerman to pay more than $52,000 to the state. The amount included $30,000 for kickbacks Hammerman confessed to taking and more than $22,000 in interest on the money, according to lawyers in the case.

Agnew alone will remain as a defendant in the civil case. But Agnew, who now lives in Palm Springs, Calif., has been excused from appearing in court because his lawyer said he would plead the Fifth Amendment against self-incrimination if called to testify. Despite his absence, the spirit of the former vice president is very much in this courtroom.

In his opening statement, David Scull, representing the three Maryland taxpayers, all of whom live in Montgomery County, argued that, in contrast to the picture of a "poor but honest public servant" that Agnew presented as a politican, he was instead a man who "entered into a scheme to divert the cash flow of the state of Maryland into his own pocket." Scull said that those funds should be returned for the taxpayers to the Maryland State Treasury.

The taxpayers are seeking $177,000 in alleged kickbacks to Agnew and $120,000 in interest.

Agnew, according to his lawyer has always maintained that he "never received five cents as a bribe or a payoff."