Restoring nuts and bolts?

Look into parkerizing. I glass bead my parts, then put them in a stainless steel 'kettle' and cook them on the coleman camp stove. Excellent results. Works especially good on hinges, latches, linkages, small springs, etc.. You can probably google 'parkerizing' and find out all you need to know. I've seen the necessary chemicals for sale on ebay but I got mine much cheaper at a chemical supply house. I haven't done this for awhile so don't recall the chemical names but I could get the dope in it if you can't find.

On a separate but similar subject, this forum once discussed derusting parts by placing them in a washing soda bath and connecting a battery charger. This worked great for me. Did my whole k-frame.