I would get as much of the rust out as you can, and shoot it before deciding on anything. It might shoot very well. I bought one like that many years ago (a T/C white mountain) and soaked the entire barrell in solvent for a week or so - then cleaned the heck out of it best I could. Went and shot it and it actually shot very well, to my suprise. I reblued the barrel and gave it to my dad for Christmas. Turned out to be a very nice gun that I had about $75 in total. The barrell still looks like crap inside really by most folks standards, but it shoots well. Good luck.