I'd shave a 1/4" off that barrel and crown it to an 11* myself. Looks pretty bad there on the final 1/4" is why. Id probably fire lap that barrel too. I don't know if you have ever fire lapped a ML barrel before Sabot, it's a time consuming pain in the butt, but it really works well for pitted bores. You could make a slug for your barrel using molten lead and a brass brush (fairly certain you know about this technique) but fire lapping has always seemed to work best for me with pitted ML barrels. If you cast your own lapping bullets, be sure to use older wheel weight lead or lead with a hardness of 11-12 or you will have problems.