Just in time for Christmas and Hanukkah shopping, New York City is auctioning gifts that were given to Mayors Koch, Dinkins, Giuliani and Bloomberg that range from the unique and exquisitely beautiful to, in the case of Rudy Giuliani, the heavily used. Mayor Michael Bloomberg’s pristine Nike Air Force 1 sneakers signed by hip hop OGs Ice-T and Fab 5 Freddy currently stand at $510—and a winning bidder can run off in them on Saturday when bids close. Meet the Gifts to the City auction, organized by the NYC Department of Citywide Administration. Bids are placed online. No shipping, so have a pick…