I would suggest Applying Brasso with a cloth. Perhaps try a tiny amount on one of the small tarnish spots to see if it works before applying it to the entire key.
Brasso is a mild abrasive (as are many metal cleaning products), so if you use it, be very sparing with it – too much/too energetic will remove the plating. I’d perhaps be inclined to ask the maker or a repairer for recomendations.
Thanks to both of you.
Yes I’m trying to email Mollenhauser and attach pics but their website will not accept my email attempt.
Maybe I have to register or join to be able to email them.
I have 3 products I’m considering using.
Eagle One Never-Dull
Flitz
Brasso