Marcy, I need a like button.
I have used a Dremmel tool. I use a wire brush on rusted bright metal but never on the black parts. I have had machines that looked like the black was rusted. It was just dried shellac. I cleaned it according to Glenn's method and was happy with the results. You can test if it is rust or dried shellac by touching either with a Qtip and a little denatured alcohol. The denatured alcohol will make it sticky - rust won't. If it is shellac you want to totally follow Glenn's tutorial. Rust is another story. It will not respond to Glenn's refinishing techniques for shellac finish. I usually try to just clean the rust off with a bit of rust remover or chrome polish. If it still has rust a Dremmel with a little brush works. The little brushes cost an arm and a leg to use so I don't use them them unless necessary. The little brushes have a tendency to fly apart and stick in skin and clothes. I always wear protective eyewear. Keep hair out of it too. Ask me how I know.