We are in the final stages of having a Steinway "D" cross-valve stack
drilled out.  The jigs are all in place.  The wood is poplar.  (Yes,
other kinds were originally used, but we've used poplar for the last
three Duo-Art stacks we've built and can give references for the
excellent performance of poplar in this capacity.)

With the jigs all made up, all that is necessary is a scale stick
to have a stack drilled out for a Steinway "A", "B" or "D" -- or
a Boesendorfer.

You must supply most other metal parts.  We did buy a box of several
hundred cross valves discarded by an Allentown, Pennsylvania,
rebuilder, and can supply those if desired.

Bruce Grimes