My approach is to start with the least aggressive cleaners and work up if the weak one doesn’t work. So basically start with dish detergent, then window/surface cleaner, alcohol, and WD-40. Acetone is the final solution, but since it melts plastic its only useful on metal or ceramic. The lettering on the NES and Commodore keys will come off with alcohol. You should always test alcohol on a small area first.

For rust, soak in white vinegar and then scrub to neutralise and remove. You should then rinse well and clean to get rid of the vinegar.

Personally I’ve only ever retrobrited plastic, but I tend not to anymore because it really does make it more brittle. Also it can be patchy on anything other than white/beige.