By 4 p.m. on Thursday, the aisles of TEFAF New York at the Park Avenue Armory should have started thinning out. Instead, dealers were still pinned into conversations, collectors crowded around vitrines, and the low roar that had echoed though the building since the doors opened for its VIP day at 11 a.m. had barely let up. “This is probably the best TEFAF I’ve seen for a long time,” dealer Sean Ke...