Those contemplating building a band organ which uses the general
cancel slot may be interested in the pneumatic register control
system which I built.  The traditional register control uses a
complicated pneumatically controlled, mechanically locking valve.
My control system is made entirely from Doyle Lane valves, is fast
acting and will control virtually any number of registers.  If anyone
is interested, I will provide the details for a few postage stamps.

Fritz Gellerman