Here is what we do to apply bellows cloth to wood: use hot hide glue
about the consistency of honey.  Apply glue to wood and put down the
cloth, heat the outside with a warm iron to remelt the glue which
causes penetration through the cloth to the rubber.  Pull it up to
check for voids in the glue.  Add more glue if needed, reapply cloth
and heat again with a warm iron.

This process insures complete penetration and eliminates any leaks in
the cloth through the glue joint.  Allow to dry and trim.

To test, close pneumatic, cover flap valve holes with tape and see how
long it takes to open.  The pumping bellows can usually be expected to
hold up to 3 minutes.  The stack pneumatics should be tested and very
tight _before_ application to the deck boards, and retested after each
one is applied to be sure the glue joint is good and any small air
channels are open.

We find it is not necessary to use clamps to hold the pneumatics to the
deck boards; in fact, clamps cause unwanted movement of the pneumatics.
We use shellac to seal the wood of these pneumatics.

We're aware that this is not necessarily the way others do it,  but it
works very well for us.

Sonja Lemon - Lemon's Player Piano Service
Sacramento, CA