Tom Gregory asks if regular pneumatic cloth is too thin for roller
organs.  The answer is yes, much too thin.  When I restored them,
I used bellows cloth for reed organs (from Organ Supply Inc., in
Erie, Pennsylvania).  This is not as heavy as pump cloth, but heavier
than motor cloth.

Some of the roller organs I restored over 40 years ago, and they are
still in good working condition.

Bruce Clark