I believe there is a difference in some Caliola rolls, although from
my research (less than exhaustive) it doesn't appear as subtle or
scientific as Matthew may have been lead to believe.  The rolls are
quite interchangeable, as we used to have an example of each instrument.

The lengthened hole theory may be someone's interpretation of a
reference in Bowers' Encyclopedia, which says the Caliola roll has
longer perforations to sound more organ-like.

Looking at my four green Caliola rolls, one notices that the titles
are, in general, more typically band organ tunes.  In fact, in
comparing the same tune on a 150 roll (yes, a bit of a stretch) you can
definitely see similarities in the arrangement, including some of the
trills and runs.

I was not able to find a duplicate tune on an APP roll.  Still, I
notice that Caliola tunes seem to have longer passages without traps.
They also seldom have long perforations, without accompanying trills
or runs, which are different than the distinctive mandolin and bell
passages seen in the APP roll.

B Bronson
Michigan