The muffler rail in a Cremona G is nothing more than a rail with
a piece of felt, something like a mandolin rail, that is activated
by the knob on the side of the case.

The mandolin in a Cremona is something like in a Coinola but different.
It is a series of little paddles in a tray made of wood that lies
under the hammer line.  As the hammer hits the strings it pushes the
paddle to the string making a mandolin sound.  I think there may be
drawings of it on the MMD website.

A pneumatic on the side of the case moves the tray with the paddles
left to right.  When not in use the paddles are between the hammers.
I hope you still have this as it is time-consuming to make.  I have
a Cable upright player with one in it just like the Cremona.  I bought
the upright just for the mandolin.  They sound great.

If my old memory is working the modulator is controlled by one tube
that goes to the turn switch on the front of the Cremona.  The other
valve in this unit works the soft pedal pneumatic.  The main vacuum
from the pump goes to one side and the other side goes to the stack.
This puts the modulator in the main vacuum line to the stack.

Don Teach - Shreveport Music Co
Shreveport, Louisiana