So I know that sometime in the future I will be looking to sale some guns that were purchased before the mandatory background check was in place. So some of the guns were bought off people at gun shows and other places. I got thinking and was wounding how do I go about getting them checked out so I know that they are not stolen. I had records on most of the transactions but unfortunately my storage unit was brocken into and the paperwork was with some ammo and they took it all. Lucky no guns were stolen and it was reported to the police. Thanks in advance for any help.