I was given a shotgun that previously belonged to my grandfather. It's a 16 Guage pump that is around 40+ years old. The past few years it was not taken care of and was left in a closet in a shop. It's accumulated quite a bit of rust. I'd like to restore it at the very minimum to where it at least looks good. I used clp and some of the rust came off. However, there is still alot on the outside. Anyone have suggestions on what to use and how? I'm unsure if using rust type removers will damage the gun or finish. Obviously it has alot of meaning to me. This may not be the best spot in the forum for this question but since it pertains to a shotgun I posted here. Any help is greatly appreciated!