Could anyone tell me a garage gunsmith way to square up a crooked barrel end? Friend of my traded for an old Rem 870 Express Super Magnum .12 gauge. Vent rib barrel sawed down to 18 9/16” length. Old discolored synthetic furniture, blueing left maybe 50% remaining. Quite nauseating to behold for a guy who keeps his firearms maintained. Friends using it for a pawn shop “leave out” gun.