Greetings;  I'm finishing the restoration of an old Willis player,
the one with seven tracker holes on each side of the tracker.  Only
one pair at a time is used to help track the paper.  When you want
to change keys, a different pair of holes is opened and the tracker
pneumatic moves the tracker bar until the holes are in balance.
An elegant idea, but slow in operation.

Anyway, the problem I now have is that I can't find any place on the
stack or bellows to get power for the tracker pneumatic.  I do see
a covered hole near the stack supply flange on the bellows.  I don't
know if that is from the factory or someone patched the hole later on.
The tubing came to me as spaghetti and I was not able to tell where
things went.

By the way, this player has an interesting way of using the soft pedal
buttons, one that I've never run across before.  I will explain it when
I get a chance to fully test it.

Thanks for your help,
Jeff Davis, in snowy Seattle