This is six years in the works," said Mary Louise Wilson, referring to Full Gallop, the one-woman play about fashion doyenne Diana Vreeland she has written with Mark Hampton. The play's opening last month at Off-Broadway's Westside Theatre Downstairs was its third official one in New York (after Sag Harbor's Bay Street Theatre and Manhattan Theatre Club productions). She has the role down pat.

"The hardest thing was to write and then perform it," Wilson reflected. "Often I said to friends, 'Let's write a show.' Mark Hampton took me seriously. We found Vreeland fascinating for years. When she died in 1989, we decided to try."

They read her memoirs, titled D.V., and found Vreeland not only fascinating but touching. The latter was not a word often used to describe the powerful V., whom even friends found intimidating. Wilson and Hampton then sought the blessings of Vreeland's two sons and got them.

What emerges in Full Gallop is a poignant, hilarious two hours with Vreeland at a vulnerable time, when she has been dismissed as editor of Vogue.

V., vulnerable? "She kept her feelings to herself," Wilson replied. "It wasn't denial or repression. She just didn't believe in displaying them. If she got depressed, she'd shine her shoes. She fought it."

Vreeland preached style in Vogue's pages, where she broke countless taboos, but also felt we needed a splash of bad taste. Her goal was to give women "what they never knew they wanted." She felt fashion was something in the air. Anyone could have it. Alas, not everyone did.

Vreeland had a reputation of being a snob. "As much as she loved titles and glamour, she wasn't reserved," said Wilson. "If you bored her, out you went. If you were interesting, you could be a punk rocker or cleaning lady. What pained her more than anything was the loss of beauty. Everyone was so terrified, thinking of her as some sort of gorgon. They didn't give much thought to her femininity. Diana had character and humor and, when young, this great figure. Men adored her!" Wilson never met Vreeland, and the more she learned about her, the more she felt Vreeland might not have been interested in meeting her. "I would've been quite afraid because of my shoes. They wouldn't have been right!"

The veteran of featured roles in countless B'way and Off-B'way musicals and plays, Wilson credits a unique aspect of her performance in Full Gallop to cabaret impresario Julius Monk, whose hit revues she worked in in the late fifties and early sixties after coming from New Orleans and finishing Northwestern University.

"We were these kids up there being witty and carefree," recalled Wilson, "creating a world which didn't really exist. Glamorous! Stylish! Julius's biggest rule was that we had to keep audience contact. That sense of connection is happening again. When I started doing the show here [Westside Theatre], I felt, 'Why does this look familiar?' "

Another repeat aspect is an audience of who's whos. Wilson was delighted with fashion designer Pauline Trigere's compliment that her mesmerizing performance made her feel she was in Vreeland's living room, where Coco Chanel and Helena Rubinstein once met to schmooze. "I'm thrilled it's working," beamed Wilson. "Could it be I'm channeling her?"

-- By Ellis Nassour