Battered stock markets be damned! Judging from the buzz and sales last Thursday at the opening night of the 56th Winter Antiques Show, the antiques buyers are back  Just ask Barbara Israel. In the first half-hour of the upscale art fair, the New York-based dealer who specializes in garden statuary sold 10 pieces, including a pair of life-size doe-and-fawn groups once owned by Doris Duke for $135,000.