I belong to the group that prefers NO reciepts or records of face to face sales. Once you see proof of state residence and have no reason to believe a person is a criminal, that's all you need. One less gun on the government books.
Except that the gun was on the books at one point in time, and if it is linked to a murder then you may be on the hook to prove that it isn't your gun anymore.
To me, this is akin to a Bill of Sale and Release of Interest when selling a vehicle. That way when the car is involved in an illegal action it won't come back to you.