NOS gold keys with acne

[bitbuster]

I bought a large quantity of NOS gold key blanks from a retired Michigan car dealer last fall. The retiree stated the dealership closed many years ago and he'd kept the keys in his garage and basement since. Many of the keys have small crusty green blotches on them. Any suggestions on how to remove this without damaging the coating of the key ? Sorry for the poor quality photo.

DSCI0639.JPG

[MBI]

I suspect the plating is already damaged everywhere you have blotches. Might want to try a soft/cotton buffing wheel, with the appropriate buffing compound for gold and other soft metals as it might help minimize the appearance of the damaged areas. If you use a gentle touch hopefully you can prevent it from stripping or flaking off the plating altogether.