Allen, I've had negative experience with 0000 steel wool on keytops. It abrades polish on plastic tops, making them a satin rather than polished finish, which is a matter of taste. I would suggest checking with the customer first. Another caveat- as an organ technician I have seen the loose steel wool fibers short circuit keyboards. I would not recommend using on Diskclaviers for example. Key polish from Yamaha or Cory works the best for me. Regards, Dale Probst Registered Piano Technician Ward & Probst, Inc. Piano & Organ Service Wichita Fall, TX
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