Herb Ziegler asks about material for reed organ exhausters and
reservoirs.  I supply four grades of rubber cloth to customers in
UK and Europe, mostly for player pianos, but I have some customers
who do reed organs.

The grade of rubber cloth depends on the size of the organ, I think,
so you need to have a look at what is there now.  There are two types
of cloth: single (having one layer of cloth with rubber on one side),
and double (having a layer of rubber with cloth either side).  One
of my customers uses the thicker grade of single cloth (C2, general
purpose on my stock list at www.musicanic.com ), but I suspect most
organs would require one of the two grades of double cloth (C3, C4).

If you are in the US, Player Piano Co. (referred to frequently in MMD)
provide various grades of rubber cloth, some of which they specify are
for reed organs.  Why not send them a sample ?

Hope that helps,
John Farmer
UK