[ Ref. Scotty Greene in 21.06.22 MMDigest ]

Scotty, Greetings from north of The Bronx! In regards to your inquiry,
without a photo of the device(s), what you're describing is a three-unit
lock and cancel system. Each pair of unit valves turns a function or an
instrument on and off.

The two main functions that require a lock and cancel unit would be the
Soft Pedal and the Mandolin Rail. The Sustain Pedal operates just as it
would in most normal player pianos. The third pair of unit valves could
be controlling a solo instrument such as pipes or Xylophone or Orchestra
Bells.

The O-Roll Scale is able to accomodate two separate solo instruments,
and also an Amplifier (for loud and soft control of percussions). You
would find the use of every possible control was only available on the
largest of the Coinola Orchestrions: the 'CO'(?) and the 'SO'.

In the 'SO', the Violin and Flute pipes would be turned on and off
together [as] the primary solo instrument, while the Xylophone or
Orchestra Bells would constitute the Secondary Solo Instrument.

(There may have been some instruments where there was a switching device
that would activate the Flute Pipes the first time the Primary Solo
Instrument was called for and -- after being cancelled the next time
the Primary Instrument was called for -- the Violin Pipes would be
activated instead, so on and so forth, etc, etc.)

I hope that this may have been of some help,

Dale F. Rowe
Bronx, New York
fredsorchestrion@aol.com.geentroep [delete ".geentroep" to reply]