Hello all,  In all my years as a rebuilder of these instruments, I have
not come across one like this so I need some help as the old tubing had
many errors in it.  I have every possible tubing diagram ever issued
but now I am stumped.  This piano is fitted with a transposing tracker
bar which I have never seen before I came to Australia.  My problem lies
with the Duo-Art On/Off switching.

All the pianos I have worked on over the years had pouch blocks which
switch the [tracker bar] lowest and highest 4 notes between the piano
stack and expression valves, depending if Duo-Art is "On" or "Off".
Some other versions just switched the holes off completely or the
vacuum to the accordion valves gets dropped for Duo-Art "Off".

This Duo-Art, however, will play the lowest and highest piano notes
through the transposer bar only (and only while transposing).  Holes
1-4 and 84-88 are blanked off on the input side (tracker bar side) of
the transposer bar with small bits of closed-off tubing.

The Accompaniment and Theme expression holes are always connected to
the expression valves and there is no pouch block control for anything,
nor can the vacuum to the expression valves be controlled.  It means
that in Duo-Art "Off", the expression levels will operate randomly if
a 88-note roll uses holes 1-4 and 84-88.

Is that acceptable?  Did they build some like this or am I actually
missing the pouch block(s)?

Kind regards,
Bernt Damm
Sydney