If you only want to make them look new try this: https://www.lowes.com/pd/SEYMOUR-St...MIr5PSnZ2S2QIVAyaGCh3AtQXCEAQYBCABEgJdaPD_BwE
I used it on a quasi-restoration over ten+ yrs ago, most bolts still look pretty decent. I also used it on the crankshaft where the seal runs, minor pitting. Impossibile to get a crank for 30+ year old MX bike.