Philip Carli asks about what he is calling it a "pump distributor"
in his post [231216 MMDigest]. The unit in the photographs is in
actuality the loud and soft pedal valve block that was introduced
by American Piano Company in 1928. It is found in all model "B"
Ampico pianos.

It is an ingenious device and operates the loud pedal, in particular,
in an improved way. The unit shown in the photographs appears to be
original, and in that case, they can leak rather badly. I do not
recommend taking them apart if you are unfamiliar with its design
and operation.

Ben Gottfried - Ben's Player Piano Service
Richfield Springs, New York
https://bensplayerservice.com/ 

 [ The Ampico B Loud Pedal Valve Block is described at
 [ https://www.mmdigest.com/Gallery/Tech/Ampico/index.html 
 [ https://www.mmdigest.com/Gallery/Tech/Ampico/amp27.htm 
 [ -- Robbie