Frank Rider replied off-list to me in response to my Caliola/APP
query.  I think he won't mind my lifting this interesting quote
from his message:

"I thought I'd tell you about my experience with one original roll
(I don't remember the numbers) that had the same tunes on APP and
Caliola.  I laid one on top of the other and the perforations were
identical.  I have an original Wurlitzer Caliola and several APP
machines and either roll plays fine on either the calliope or the
pianos. "

Also Bill Black sent some very telling evidence that APP and Caliola
rolls were (sometimes or always?) identical.  He has a roll in his
collection that has two end-numbers (Wurlitzer collectors should know
about those hidden "end-numbers"), one being a 4-digit Caliola number
and the other a 5-digit APP number.  That roll at least was marketed
under the two different labels, each with its own roll number.

Bill goes on to report:  "Having played a number of the APP rolls and
the Caliola rolls on my Caliola, it seems that some of the ones with
the APP numbers sound sort of choppy when played on the Caliola. The
ones with the Caliola numbers don't seem to have this effect. "

Matthew Caulfield