Since the OP , as stated in an earlier post, now knows the correct serial number.... My thought is the easiest way around the whole question would be to buff off the number on the butt, and have the correct number re-stamped. Done deal. The chance he will get jammed up with the gun as stamped is slim, but why risk it?

My experience with serial numbers - Back when I was 16, I was driving home from duck hunting down in the Lordship marshes in CT with a Mossberg 500 pump laying on the back seat of the car. Got stopped for a loud muffler, and ended up sitting in the Bridgeport PD station for about half an hour, as serial number "500" was a "stolen gun". Finally a more intelligent officer came into the equation, who knew it was a model number, and that these pre-1968 guns did not have serial numbers.

As a LEO, seen lots of guys trying to run assembly numbers in the NCIC system for stolen checks / evidence documentation. Have had FFL dealers do the same on sales paperwork.

Larry