I 2nd the porcelain patch paint. I used it on a chip in stove, 2 years of scrubbing stove chip still covered. I got tiny bottle at home depot bet ebay has it with free shipping
I'll check out the porcelain patch paint. Sounds interesting. What do you use to write on it that remains readable after many scrubbings?
I checked the registers out yesterday afternoon while there shelving books. There are two registers and the keyboards are different. They were probably donated. Eight area churches of different denominations went together to create it. There are some overhead costs for utilities and maintenance but no one there draws a salary. It's purely volunteer and we think cheap.
All the keys I need to mark are on the periphery so I can mark on the chassis to direct attention to them. This is going to be easier than I thought. I'm thinking fingernail polish and a fine brush may be the way to go though the porcelain patch paint sounds interesting.