I don't see much damage, maybe some JB Weld for cosmetics. or, saw off 4" of barrel and then notice it is too short to be a rifle any longer and then weld on an extension to make it legal. or, get another barrel and install, maybe let someone else do it. Sell old barrel to someone who is building a pistol. but to save it, cut it off to where it can be crowned and the WELD a permanent brake/shroud back to legal length, check with regulations before doing this.