Stephen Powell asks about a set of Ampico A expression units
[190520 MMDigest].  I have a set of intensity controllers from
a complete Franklin upright foot-pumped Marque Ampico.  These are
unrestored but there is no crescendo system with this design.
I am not sure if there is the re-regulator pneumatic on this model.

I did make a set of expression regulator and crescendo units to
suss out [understand] the design and the likely problems in building
a real set.  The crescendo box is very critical with regard to
leakage around the Fast/Slow crescendo valve.  This is the reason
Amphion used rubber cloth diaphragms and small springs to stop any
parasitic leakage.

Paul Rumpf
Melbourne, Australia