The best-known campaign fund in U.S. political history, Richard M. Nixon's 1972 Committee for the Re-Election of the President, has finally paid its last debts. Some of the most famous people of the Watergate era, and their lawyers, are the beneficiaries.

Former attorney general John N. Mitchell and some of his attorneys received $68,579 just before Christmas. Sally Harmony, the former secretary to Watergate burglar G. Gordon Liddy, got $2,239 for legal expenses.

The payments, big and small, are reflected in the latest report of the 1972 Campaign Liquidation Trust, the sole legal survivor of the Nixon campaign organization known to its critics as "CREEP."

In all, the trust doled out $588,877 in the last three months of 1984, leaving only $19,938 in the bank, according to records on file at the Federal Election Commission.

The chairman of the trust, Guilford Dudley of Nashville, Tenn., said yesterday that he'd like to hold a party with the surplus, but instead will turn over whatever remains to the Republican National Committee. Dudley, named a trustee in 1972 by then-GOP National Chairman George Bush, is happy that it's nearly over.

"Everybody has agreed, I think, on the amount that they're getting," Dudley said yesterday in a telephone interview. "But the actual closing out is for the lawyers to do . . . . We're mighty glad to get rid of it."

The biggest final payment, for $275,300, went to the Washington law firm of Ginsburg, Feldman & Bress for legal fees of former assistant attorney general Robert C. Mardian. His conspiracy conviction in the Watergate cover-up trial was overturned on appeal.

Former Nixon campaign finance chief Maurice H. Stans came next, with a $117,044 payment for various expenses. He and Mitchell were acquitted in 1974 on charges of blocking a probe of financier Robert L. Vesco.

The fund's trustees decided not to pay legal bills in cases where the defendant was convicted of a crime. Watergate conspirator Liddy, who spent more than four years in prison after conviction on burglary and wiretapping charges, submitted a bill for $70,000 anyway, for legal bills rising from civil litigation with the Internal Revenue Service.

Liddy said he was entitled to the money because the allegation that he had absconded with excess reelection committee funds was based on unverified testimony before the Senate Watergate Committee. But he finally withdrew the claim.

"I think they finally convinced him he was just going to hold the whole thing up for no good reason," Dudley said.

The trust once contained about $4 million, but much of it was paid out in earlier years, largely to the Democratic Party in settlement for the June 17, 1972, break-in at Democratic National Committee headquarters in the Watergate complex.

The fund's remaining assets were then tied up for years while the Internal Revenue Service threatened to hold the trust liable for gift taxes on donations to the Nixon reelection committee. Dudley said the IRS finally relented last year and "that cleared the decks."

Former Nixon campaign committee lawyer Kenneth Parkinson, the only Watergate cover-up defendant acquitted at the jury trial before U.S. District Court Judge John J. Sirica, received a final $38,758 pro rata payment for the legal fees he incurred.

Perhaps the biggest winner was Anthony T. Ulascewicz, the former New York City detective who began as a private investigator for Nixon in 1969 and wound up delivering hush money to the Watergate burglars. To keep his identity secret, he was never listed on the reelection committee payroll.

"Nobody wanted to know Tony Ulascewicz once Watergate broke," he said last year. "I was kind of lost in the shuffle . . . . I'll probably have to get in the end of the line."

The trustees awarded Ulascewicz $22,180.29 in back pay. CAPTION: Picture 1, Maurice. H. Stans . . . received $117,044 for expenses; Picture 2, John N. Mitchell . . . shared $68,579 with attorneys; Picture 3, Anthony T. Ulascweixz . . . received $22,180 in back pay.