Originally Posted by
Steve M1911A1
OK, it's a genuine Colt.
Somewhere nearby it might say something like "Frontier Model," which would indicate that it's .44-40, or ".45," or "US Government Ctg.," or something like that, telling you that it's .45 "Long" Colt.
It could also be .38-40.
Keep it covered, inside and out, with a very thin coating of good-quality gun oil. If there are visible rust spots, rub them out with nothing more abrasive than a small chunk of soft balsa wood (from a hobby shop) and a little oil. Every time it gets handled, wipe it down with a slightly oily rag.
For almost set-and-forget rust proofing, you could spray it with a coat of Boeshield (from Brownells).