A very precious board, so anything not extraordinarily
safe is right out.
If this board is so valuable - don't ask us. Go to the experts, like a
museum or college that has a curatorial program. The number one rule
about museum restoration is *never* to try something that you are not
*very* skilled at.
I have found that the professionals can generally get anything off of
anything without leaving anything. Quite amazing.
William Donzelli
aw288(a)osfn.org