Search:

Replacing is the safest and most sure way to get
it to where you know exactly what it is going to do
when you use it. From this keyboard I see no special
value in the old leather.

+1
The issue is that it may be loaded with any grit.
I have some loose 8000 grit on leather for kitchen
knives and it does sound a lot coarser than my
8K Norton but may give about the same polish...