The Duchess of York, who visits L.A. this week, apparently wants to blend in with the natives. Before making the trip stateside, Fergie popped into the Uvasun Centre, a tanning salon in London's Mayfair section where she's a regular, for one of its 45-minute, $50 "hotbed" treatments. Although Uvasun requires women to sign a statement that they're not expecting, the Duchess, who is four months pregnant, presented a letter from her doctor okaying the ultraviolet treatment, thereby waiving the salon's liability should her baby arrive wearing sunglasses.

Celebrity costumer Bob Mackie does do windows—Bloomingdale's. Beginning April 6, the New York store will feature nine new Mackie gowns on look-alike window mannequins of Greta Garbo, Marlene Dietrich, Diana Ross, Grace Kelly, Audrey Hepburn, Marilyn Monroe, Joan Crawford, Shirley Temple and Elizabeth Taylor. Copies of the black, white and silver dresses will be on sale for $3,400 for a Hepburn to $10,000 for the beaded Monroe number. Meanwhile, Bloomie's fourth floor will offer a Mackie not-for-sale retrospective of Cher outfits, including the Road Warrior getup she wore to the Oscars in 1986. He's not predicting which outrageous outfit she'll wear to next month's awards. "She hasn't called me yet," he says.

When NBC's St. Elsewhere dies this spring after six seasons, it's taking Dr. Elliot Axelrod (Stephen Furst) down with it. His excess weight leads to a major heart attack. Producer John Tinker won't give a prognosis, but you don't need a medical degree to tell poor Dr. Axelrod's fate. The show's title: Requiem for a Heavyweight.

Peggy Lipton, whose Julie Barnes character from Mod Squad was as cool as they came in 1968, dropped out of acting after marrying composer Quincy Jones in 1974. Now split, she's returning to ABC on March 28 as a district attorney in Addicted to Love. Barry Bostwick co-stars as a gigolo she prosecutes.

Future credits: Glenn Close, whose baby arrives late next month, is a good bet for the leading role in Les Liaisons Dangereuses for director Stephen (My Beautiful Laundrette) Frears and Lorimar. Last year she almost played the part on Broadway....Hunky Dennis Quaid, whose DOA opens March 18, is set to play Jerry Lee Lewis in Great Balls of Fire. His publicist says Dennis hopes to do his own singing and piano playing....And singer Tom Waits, an alcoholic bum in Ironweed, is going to play another one, at least part of the time, in Franks Wild Years for Island Pictures. He's already done Wild Years as a stage musical and an album.

Lily Tomlin's Ernestine, that nasally know-it-all switchboard operator, is coming out of retirement to place a call for Mario Thomas on her ABC Free to Be a Family special next Christmas. Ernestine tries to connect children of the United States and the Soviet Union, but after much officiousness, she misdials and connects the U.S. with the garment workers' union.

Spike Lee, who directed and stars with Chicago Bull Michael Jordan in those new Nike TV ads, spoke up at New York's downtown Tower Records last week. Spike complained that the sound track for School Daze, his latest movie, was on the third floor rather than the first. "That's where the Less Than Zero and Good Morning, Vietnam sound tracks are," huffed Lee. The manager said okay and moved the Daze albums down two floors. "Spike shops here all the time. He deserves to be on first," he explained.

When actress Pamela Springsteen, Bruce's 25-year-old sister, had to play guitar and sing for her new movie, a teen horror flick called Sleepaway Camp 2, "the result was certainly not up to Bruce's standards," reports director Michael Simpson. "But I told her not to worry. Bruce probably couldn't hold a candle to her acting."