I had this real bright idea I would polish the derby cover on my wifes Fat Bob. The mothers powerball slipped and barely skipped across the wrinkle black. My first thought was that the mag wheel polish was just down in the wrinkles and it left a greyish mark on the primary cover. But I have not been able to get the grey off??

Any ideas??

 

Soft bristle toothbrush and dishsoap.

 

Try cleaning it with a little wd/40 and then spray the primary cover with Pigspit...