Can anyone help decipher what this is? The last two digits do not match the serial number either. This is stamped on the front strap of a six digit Colt that dates to 1917. Much thanks fellas...

I need to sell an Ithaca M1911A1 for my late fathers estate and I am pretty handgun ignorant. It is marked "M 1911 A1 US Army". It has these markings: "P" on top of the slide, "P" between the trigger and the handle, "FJA" between the trigger and the handle, "C" on the other side of the gun on...