Three men described by federal law enforcement officers as top-echelon racketeers in the downtown D.C. bar scene were sentenced to prison terms yesterday for their involvement in cocaine trafficking.

The sentencings of David A. (Shaggs) McGowan, Richard A. (Ritchie) McCaleb, and Joseph S. (Joe Winters) were seen by the government as the most significant step in a lengthy investigation and prosecution of cocaine distribution from Swiderski's restaurant at 21st and M Streets NW.

The restaurant, Sylvester's, which bills itself as the city's only Polish pub and serves Krakus beer and kielbasa sandwiches, now can be seized by the government because it has been found to be the center of a criminal enterprise.

The actual seizure has been postponed for at least five days, however, pending further legal arguments by Swiderski's attorney concerning the dissolution of the business.

Swiderski, who has no previous convictions, was sentenced to a prison term of two to six years and fined $5,000. U.S. District Judge John H. Pratt allowed Swiderski to remain free on bond pending an appeal of his guilty verdict.

McGowan, who has three prior felony convictions on charges that include gambling as well as prior misdemeanor conviction for shoplifting a package of bologna, was given a prison term of four to 12 years and was fined $3,000. He must enter prison by Dec. 15.

McCaleb, who has one prior gambling conviction, got a prison term of two to six years and was fined $10,000. He must enter prison by Dec. 15.

McCaleb, who has one prior gambling conviction, got a prison term of two to six years and was fined $10,000. He must enter prison by Dec. 15.

Much of yesterday's sentencing centered on Assistant U.S. Attorney Barry Leibowitz' attempts to depict McGowan, McCaleb and Swiderski as major criminal figures whose convictions showed that gambling profits were being channeled into illegal drug trade.

Law enforcement sources have described McCaleb and Mcgowan as the top two lieutenants of admitted gambler Joseph Nesline, who is described by those same sources as the major underworld figure in Washington. Nesline, who five years ago said his last gambling venture was a casino in Yugoslavia that failed miserably, has denied the "underworld czar" designation in the past.

At one point during yesterday's sentencing, Leibowitz appeared to be beginning a description of how McCaleb and McGowan worked for Nestline, when McCaleb's attorney objected vigorously.

"I know about Joe Nesline," interjected Judge Pratt. "He (McCaleb) is not being sentenced for that."

McCaleb's attorney, Plato Cacheris, portrayed his client as someone who merely made a foolish mistake when he agreed to finance an illegal venture-the importation of a large quantity of cocaine from Columbia-and was not a major criminal figure.

Swiderski was described by his attorney, James Lyons, as a hard-working former bartender who built up his restaurant from scratch "busting his tail" with hard work. The loss of the restaurant was a severe punishment already, Lyons said.

Swiderski said he wanted to give the Polish people "something to be proud of, because of the jokes," and that was the reason he opend a Polish bar.

But, he added, "What they say about the Polish people may be true. I'm guilty of stupidity. I've let the Polish people down."

McGowan's attorney, Fred Joseph, said his client was merely a cocaine user and not a member of any organized criminal element.

"The specter of organiized crime has been thrown into this case from the beginning," but the government has been unable to prove it, Joseph said.

McGowan said he had never sold drugs for profit, but "I've shared them with my friends and they share it with me."Leibowitz told the court that the government is trying to stop "this criminal element in downtown" and wanted the defendants' cooperation to reach the strata above them. "These men have come up with nothing but garbage," he said.

Law enforcement officials here said the joint federal-District investigation into cocaine trafficking here has been one of the most successful undercover drug operations even conducted here.

The investigation led to 25 convictions out of 27 prosecutions. Of the 23 persons who have been sentenced, 11 received jail terms and 12 were placed on probation.