So I have my great grandfather’s Colt 44 revolver. I believe it is a model 1860 cartridge conversion. Unfortunately the cylinder was blown apart some years ago with a misfire. Now I already know it’ll likely be a pain to get the cylinder replaced. My bigger question for y’all is, does anyone have any idea why the patent number is blank? Everywhere the patent number would be listed it is nonexistent. It’s definitely not worn off, it just looks like it was never stamped. Any ideas?