Hes, Well I guess you are on the right track, clean em up and see if they are in good enough shape for a build. Are the breeches threaded? If so you need to see if it is a standard thread and not worn or rusted to make them unsafe....If not threaded, then you need to drill, and thread them. There were instructions on this site for making breeches and breeching a SXS, not an easy task....I know I am making some right now...There also is a book out on this subject "RECREATING THE DOUBLE BARREL MUZZLE LOADING SHOTGUN" by William Brockway....GOOD LUCK...Ed