My friend Nisan has a Mason & Hamlin T-100 Welte that is in very good
working order, probably restored about 10 years ago.

The problem is that the Bass crescendo pneumatic has a small hole in
the corner.  I patched it to get it to play for him; it worked fine
for about three months, but then the patch has worn out.  He needs to
recover the pneumatic but can't see how to remove it from the
mechanism.

Is there anyone out there that can instruct me on how to disassemble
the T-100 German Welte?

Eli Shahar