As a follow up to Bob Baker's remarks re the Aeolian player organs,
let me point out that there was both the regular Aeolian Player
Organ, and the Aeolian-Skinner Duo-Art Player Organ.

The regular Aeolian Player organs did not have provision for any
automatic register changes.  There are indications printed on the
roll for the operator to follow should they wish.

On the other hand, the Aeolian-Skinner Duo-Art Organs rolls are much
wider and have much greater resources, including automatic registration
and swell shade control.

For some reason, the regular Aeolian Rolls that I've seen have been
all in excellent condition while the Aeolian-Skinner Duo-Art Rolls
that I've seen have mostly been so brittle that they required the most
delicate care and handling.

For what it's worth...

Hal Davis