I have a 22/45 MK II or maybe its a MK I, the case is buried away and im lazy. Id check the barrel but I have a pac-lite on it now. Anyway, its an old hand me down and Im thinking about replacing the guts, there is some rust in there. Would it be worth the time and investment upgrading the internals? I bought the pac-lite because I wanted to put a suppressor on it. My plan was to shoot the barrel out and then get one of those gucci Volquartsens; i probably never will shoot the barrel out so I doubt ill ever get one of those. Also, can I still get magazines for this gun? Between all the different Ruger 22 pistol variants, im not sure what to get. Finally, where should I go for parts?Thanks.