Larry Norman does indeed have a treasure (1930 Weber Duo-Art for sale,
in 121203 MMD).  When Aeolian introduced its automatic roll changer
for pipe organ and piano around 1930, it was just too late to catch on.
Roll changers were not that unusual in other machines, but the Aeolian
Duo-Art introduced a system that would play ordinary rolls.

Wurlitzer, on the other hand used, special rolls that had a special
leader that incorporated a rod to engage with the changer mechanism.
Being a commercial machine, the Wurlitzer mechanism is robust and most
reliable.  Changers are also common on Hupfeld and other machines that
were designed for public service.

It was Aeolian's concept of using ordinary, off the shelf rolls, and
selective remote control, that made its system unique.  The rod used
to engage the changer was not part of the roll, but rather, entirely
loose from both the roll and the changer.  To make this concept work,
the removable rod was held by clips in the revolving drum, and the roll
attached to the rod by its normal D-ring.  A very late modification by
Aeolian-Skinner introduced a scheme that had no rod at all.

The pipe organ Duo-Art Concertola seems to outnumber the piano
version substantially.  In both styles, the mechanism is primarily all
pneumatic.  The roll selection trigger is electric as are the remote
control functions of repeat, rewind, and program play.  I have
schematics for anyone that might take Larry up on his offer.  Others
on MMD have information, too.

My organ Concertola can be seen in operation at

  http://aeolianorgan.com/aeolian/Movie.html 

Maybe you'll decide you need one of these, too!

Bob Taylor
Missouri