Although it looks like cracks, they’re just time marks, Alan. The surface of the keys remain smooth. It is even interesting that you have asked because in all the copies I have seen of this model, practically everyone has these marks. About Gui Prioli, thank you.
Daren, I have a condenser microphone at home that would do this job well, but all my equipment is stored. When I go to use it, I take the opportunity to make a recording.