Just a note about the split point: My Duo-Art mechanism (still don't
have a piano for it) has 88 notes in the stack.  Right now it's in
pieces and is waiting for me to continue restoring it, but one side of
the stack has 43 notes, the other 45.  I would say that this coincides
with the 43/44 split point for the smaller stacks.

Eliyahu Shahar