The Colt Ace was a 1911 chambered in .22. Basically a pistol made to practice with, but was a true 1911, in .22. From what I have heard, a hood majority of Colt parts are interchangeable. Not 100% sure on the Ace frame #'s, but it could be worth more if it was rare. I'm not that knowledgable about Colts to tell you, but Andy @ Blackwing could tell ya.