...sounds good GrandpaGlennO. I've heard about it but never tried it. WHITE vinegar...just have to ask, how about Yellow?
Denny, a friend of mine that runs a resto shop uses a fine grade of sand in his BIG tumbler and does a nice job. He pitches it in and lets it tumble overnight. Not saying it'll work for you but just info. Maybe we need to give the vinegar a try?
My thinking is if the bolts are pitted the pits wills till show unless its tumbled to smooth up the SMALL pits? But then Denny, your not wanting a show piece. Hey worth a shot!!