I'm cleaning up the parts of a little Hopkins & Allan falling block .22 at the moment and there are hours of careful work with needle files and diamond laps in involved in "improving" the original finish and removing as much of the damage as can be removed. It's something you either do because you enjoy it so much or because the piece is worth the effort. A surface grinder or a rotary power lap are useful tools for this sort of job. Buffing wheels have no place in the process if one wants to achieve anything like an original appearance with crisp edges etc.