This may already be well known but I used a gun & reel cloth with silicone to clean up the tarnish on the feet and it works great. It states on the package that it cleans and protects metal, plastic and wood. You can get them at Walmart for a couple dollars. It shines them up just like new.
The Cosmic Rust Isuue. Yah I used some alcohol swabs and then use clear nail polish to seal it from happening again. That was 4 to 5 months ago and it has not returned.