I have a friend with a PSR-2000 that has worn all the paint off the keyboard case surrounding the volume control. The reason behind it is that when he turns the volume knob, which is almost constantly, his fingernails are resting on the keyboard case. I repaired it with Krylon then put a thin, Lexan shield over the area for protection. Within two weeks he had scratched the Lexan cover to the point where it looked like it had been gouged out with a pocket knife.
Prior to me making the repairs, he swore his fingernails never touched the keyboard case when turning the volume knob.
Here's something many folks just don't think about. The reason that car door handles have shields behind them is because years ago, when they didn't have the shields the paint in that area quickly wore off. If you were to rub your finger on one specific area of your car 50 times a day, within a few months that spot would likely be worn down to bare metal.
From my perspective, keyboards, all keyboards, are built like tanks. I've seen every kind of player pounding on the keys, punching the buttons, hammering joy sticks, jamming pitch bend wheels and massaging touch screens. Some perform 5 to 7 days a week, several hours a day. Despite the abuse, the vast majority of those keyboards continue to function as good as they did the day they came out of the box. The big difference in appearance after a few years of gigging was dependent upon the owner and the way he or she operated their equipment. Some keyboards looked as if they had been dragged behind a truck with a length of chain and were just a few months old, while others that were several years old, and used ever day of the week, looked just as good as they did when it was shipped from the factory.
As for hand lotion, yes, this can have some effect on any finish--even stainless steel. But, when my hands were falling apart I had to use prescription hand creams and lotions extensively and it never damaged the finish on my PSR-3000s, 2000s, 740s or 5700s. I sincerely believe that abrasion is the culprit for any paint wear problems. And if your hand lotion is volatile enough to remove paint, I would think it would be disastrous to your hands. I could be wrong about this issue, but then again, maybe not.
Good luck, and I hope you are able to solve your problem,
Gary
[This message has been edited by travlin'easy (edited 09-09-2010).]