As mostly already said, not worth a lot of time and money attempting to fix them. However, one thing you could do is just wipe them with any kind of Oil. Even motor oil. If already starting to RUST, and with those rusting is the correct term, if you want to spend the time, just wipe oil on them. Then wipe off any excess oil. Do not use any water based solution since if the Zinc coating is going, the Steel inside will rust faster. I never could figure out why so many people spend time and money reservicing or replating them. IF you go to a coin show, usually you'll find those with Zinc or Tin or Chrome or even Copper plating. I like the Copper plated ones best.