It pays to have the right connections. Lew and Edie Wasserman and 700 guests were celebrating their 50th wedding anniversary last week on the back lot of Universal Studios. As Motion Picture Association of America President Jack Valenti and his wife Mary Margaret walked in, Wasserman, the head of MCA/Universal, quietly and mysteriously told Mary Margaret, "I have a gift for you."

When she sat down at her table, Mary Margaret Valenti discovered Wasserman's gift: Her dinner partner was "Miami Vice" star Don Johnson. At one point, even film legend Audrey Hepburn came over to get Johnson's autograph. Valenti said his wife told him she couldn't wait to get home to tell their 17-year-old daughter Alexandra. "It will blow her mind," she said. Sure enough, Valenti added, Alexandra was impressed. And that is something, since anyone with a teen-ager at home knows just how difficult teen-agers are to impress.

Britain's Wedding Fever

Royal Watch: It's going to happen. The day after tomorrow, Prince Andrew and Sarah Ferguson will be married in Westminster Abbey. This wedding won't be as glamorous as the wedding five years ago of Prince Charles and Diana, but London is excited. And Sarah is the one who counts. The tabloid Sunday Mirror yesterday devoted eight full pages to the impending marriage, with 14 photographs of Ferguson and only one of Andrew's face and four of the back of his head.

Londoners seem impressed with Ferguson's puckish sense of humor and that after marriage she intends to follow nonroyal behavior and actually work for a living. She plans to continue as executive editor for Geneva-based BCK Graphic Arts, which produces art books and catalogues. According to Burke's Peerage directory of the nobility, it's the first time a princess so close to the throne will continue as a career woman.

Out and About

Congressmen usually like to see movie and television stars visiting the Hill. But these days the stars are coming to town to lobby for changes in the tax bill. Ed Asner, former president of the Screen Actors Guild, is to make the rounds of congressional offices today, arguing for the reinstatement of tax deductions for such acting work-related expenses as publicity photographs, special clothing and agents' fees. Tomorrow, actor Tony Randall will be talking with the conference committee members. Last week, Colleen Dewhurst and Cliff Robertson made visits to congressmen on the same issue and Charlton Heston did some lobbying by phone . . .

That was Patti LuPone, the star of the hit Broadway musical "Evita," filming on the steps of the Capitol yesterday. She's here filming the NBC movie "LBJ," in which she plays Lady Bird Johnson. LuPone and a group of 10 others from the cast and crew showed up Friday night at the Fairfax Bar of the Ritz-Carlton Hotel to hear Peter Robinson play the piano. Then, to the surprise of the customers, LuPone sang "Don't Cry for Me, Argentina," the hit song from "Evita," and "As Long as He Needs Me," a song she sang in "Oliver!" . . .

*And a sad note: Andre the Seal is dead. Time, as it must to all seals, caught up with him. The 25-year-old seal was last seen in June, appearing tired and depressed after losing a mating-season fight. Andre was well publicized over the years for his annual swim to Maine after wintering in southern New England. His trainer, Harry A. Goodridge (who had found Andre as a 2-day-old abandoned pup), said Andre's body was discovered Saturday on a deserted stretch of shore in Rockland, Maine, about eight miles from his summer home. Andre was buried in Goodridge's back yard with the proper ceremonies. On Andre's loss of will to live after losing the mating battle, Goodridge said, "He used to be king when he was out free. I think he has been dethroned due to his age."