Howdy
MOST(not all) CMs will be engraved with the last four of the serial number on the bottom back inside of the slide and also on the bottom of the barrel. It might be possibl;e for you to get a new one piece barrel depending on the outside dimension of your barrel muzzle. They made two different size barrels. I think 300 is a good price, I've paid that much for frames. 1911s should be a little loose. There is also a good deal of info on the Detonics Collectors group on yahoo, check it out...
L8r
Conley