I am trying to locate a rebuildable early Duo-Art pneumatic stack
for a 1922 Steinway A3 (T20-17-31-20B).  I have two similar stacks
but without the correct spacing (T26-20-21-21B) and T26-28-17-17B).
I would like to buy a stack I can rebuild if one is separated from
a piano and available.

Ed Joganic