Sotheby's forthcoming Space Exploration Auctions features a couple of interesting Omegas, Deke Slayton's gold commemorative Constellation and Gennady Padalka's flown X-33: http://www.sothebys.com/en/auctions/ecatalogue/2018/space-and-exploration-n09897/lot.87.html http://www.sothebys.com/en/auctions/ecatalogue/2018/space-and-exploration-n09897/lot.286.html Perhaps forum members will pick them up...good luck!
The Constellation sold for USD 23,750* and the X-33 for USD 25,000*, both comfortably in excess of their original estimates. *Includes buyer's premium.