I have two very low mileage (<1000 rounds) gray Colt 6600 1/7 upper receivers circa 1985. Each has a bayonet lug. Complete except for Bolt/Bolt Carrier/Charging Handle, $400.00 plus shipping. Will add the factory head-spaced bolt (bolt only) for $55.00. Looking for FF RAS, RAS II, Aimpoint M2/ML2 in partial trade. USPS money order only (or one U.S. Eagle $50 gold coin).