Yeah Freebird, send it to Ed Rayl or Bob Hoyt and have them rebore it to the next larger caliber for about a hundred bucks.

Actually, the best thing to do is get the bore as clean as you can and give it as good a polish as you can with J-B Non-Embedding Bore Cleaning Compound. Then shoot it and see how it does. It may be quite accurate even with a bit of pitting.

As far as reboring goes, it may be worth the money because you'll end up with a quality bore from either one of those guys. Whether it can be rebored depends on the current caliber and size of the barrel. If the barrel is 15/16" and .45 caliber it can be rebored to .50 caliber. If it's a 15/16" .50 caliber it might be rebored to .54. I'm not sure - you would have to check with one of them. If it's a 1" .50 caliber it can be rebored to .54.

I would deal with the bore first, before working on the outside. Then you can shoot it and see what you have. Even assuming a rebore is not in the cards and accuracy isn't so great, it may be something you'll enjoy shooting now and then or hunting with at distances within the accuracy limits of the barrel. If accuracy is really crap and a rebore is not possible, hang it on the wall and drink a toast to it now and then.