I had the great pleasure to visit that place several times when I was
working for George Cooper. We built the O-roll frames, player accordions,
drum beaters and several other parts that went into the machines. We also
toured the Aeolian factory in Memphis which was awesome. Those visits are
forever etched in my mind.

As far as the suction box modulator, I do not know exactly how it was
used except that a hose from the roll frame controlled the vacuum cutoff
during rewind.

I have serviced a few of the Aeolian suction boxes and they seem to have
some odd problems. I usually remove the entire modulator and sometimes
build a new box for the motor with a new pouch cutout valve installed in
the main vacuum line.

It is best to completely disassemble the motor unit to see if any
insulating material is blocking the ports. You may want to replace the
suction motor if it has a lot of hours of usage. I can't remember if
there is a vacuum reservoir with a spill valve, but if not you need to
squeeze one in somewhere. This regulates the vacuum to a constant level.

When working on the stuff under the keyboard, raise the instrument up
about a foot on sturdy blocks to save your back.

As to the Aeolian piano stacks, the black foam valve seats often get
hard and squashed down with age. The valve blocks are very hard to
rebuild and I have never found a good way to crack them open. Maybe
someone else knows some tricks.

The nickelodeon is a difficult beast to service due to the way it is put
together. I suspect that you will have to remove every part of it to do
a proper rebuild. Watch out for Wurlitzer style valve blocks with plastic
pouches, as that was what we sold in the early days. Later units had good
leather pouches. Those valves were used on the lock and cancel unit, roll
frame, and percussions.

The roll frames had a crude belt drive with 3-step pulleys to set the
tempo. They have exposed electrical terminals that are a shock hazard,
so never stick your hand in there when the unit is plugged in. You should
install a protective cover over that area if possible.

I could probably write a lot more about those machines, but for now reply
if you have specific questions and I will try to give you an answer.
There must be about 100 of those nickelodeons stored away in sheds and
back rooms, and I doubt that any of them still play after all these years.

Gordon Ramsey - Ramsey Music Service
Wichita, Kansas