I am sending the following email to folks that are restoring Coinola X's.
Actually the shelf in the bottom of a Coinola X is for the bass drum
only.  The shelf has lock and cancel valves for soft pedal and a single
valve for sustain pedal, as well as the three valves for the bass drum
and the two tympani beaters.

As you look to the right, directly behind the bass drum shelf is the
junction block that feeds the xylophone and has a hose going to a lock
and cancel unit for xylophone and mandolin units.  There is a cut-off
pouch in the junction block for the xylophone vacuum supply.

The lock and cancel unit has a hose going to the loud soft unit that
controls vacuum to snare drum unit that has another lock and cancel to
work the loud soft unit.  There are also two valves in it to work snare
drum roll and single stroke drum.  There is a tee in the supply line
for the triangle wood block valves in the supply line to the snare drum
loud soft unit.

There is also a 3/8" or 5/16" tube in the lock cancel for mandolin and
xylophone as well as a nipple for the coin trip pneumatic or there is
a tee that goes to a block mounted either under the keyboard or mounted
to soundboard above the high notes on the xylophone that has two rows
of nipples with bleeds in it and there is another set of nipples with
bleeds on the bass side under the keybed for the bass drum shelf.

The bleeds for everything in the bottom of the piano are in those two
units.  The supply for the bleed unit on the left unit is on the bass
drum shelf next to the one inch vacuum supply.

Most of the above applies to Coinola X models that have the vacuum
reservoir on the back of the box pump.  Other Coinola X's have the
vacuum reservoir in the bottom left of the piano but are basically
tubed the same.

Don Teach - Shreveport Music Co
Shreveport, Louisiana