This weekend, the Park Avenue Armory plays host to the  New York Antiquarian Book Fair —i.e., Mecca, for a certain type of bibliophile. At the press preview, I’m conspicuously underdressed, having (lazily) assumed bowties and sweater-vests would rule the day in this crowd. Instead, it’s a sea of chic blue suits. Multiple dealers arrive in sequined floor-length cocktail dresses. At the Bruce McKittrick Rare Books Booth, all the purveyors wear flowered headbands. Visitors skew more eccentric. Leaning against the Armory entrance, I spy a fellow in cowboy hat and bright chartreuse pants. Which is all to tee up my first question: who  are  these people? A rare Eve Babitz.…