Hi,  I'm restoring a 1906 UK Aeolian Upright 'Pianola' player piano in
California which has the Themodist system incorporated.  (I bought it
in the UK 8 years ago, no room to do anything with it until I moved to
the US.)

Whilst checking out my tubing requirements underneath the keybed I made
an unfortunate discovery.  I appear to have a section missing!  I was
initially curious when I could not work out how the foot pump output
connected to both sides of the pneumatic stack with no junction
visible (it was not all connected up when I bought it).  Also,
connections from the tracker bar, through a valve unit next to it (left
hand side) ended under the keybed as loose tubes.

On further investigation I found that the Bass and Treble adjust levers
do not actually connect to anything, and then I saw the 'shadow' (screw
holes and slightly cleaner wood) of a unit which obviously directed the
foot pump supply to both sides of the stack, controlled by the bass and
treble levers or from the tracker bar/scroll.  Reading up it appears
that I do indeed have the expression box missing.

My call for help is if there is anyone out there that has the unit I am
looking for, ideally complete, though I do not mind restoring it, I
would like to purchase it to allow me to complete my project.

Thanks for any help or information that can be given.

Mike Green, Capitola, CA