Hoping someone can shed some light on a 1981 Colt ACE .22lr auto pistol, 'signature series'. It's Colt blue, w/Custom Shop medalion Cocobolo grips; French-fitted Walnut presentation case. Signature of Sam Colt w/years '1836-1981' on left side of slide, next to relief panel gold-plated Colt dome and unfurled banner. Right side of slide has Colt family crest. One of 1,000 units, n.i.b. What's it worth? Family member wants to sell, but has no idea of value. Any and all opinions will be appreciated!