Hi from Maine -- You mentioned me in your MMD posting about the
stack division location.  As I recall, it's D# (above Middle C) for the
bass and E (above Middle C) for the treble.  The Simplex player (and
others) were E and F.  The Ampico was F and F#, for bass and treble
divisions.

I never counted the key numbers here since I was always thinking
musically.  Sometimes when I was rushed, I put the theme on bass plus
treble for an instant, since the key was usually isolated and it didn't
matter!

By the way, there were some Aeolian rolls (Themodist 88 and Duo-Art)
which were off by a note, using the Simplex action division, so even
that company made mistakes in that regard from time to time concerning
their player rolls.  QRS and some other independent roll manufacturers
published a few articles in the trade journals during the 1920s saying
what an error it was to have the bass-treble divisions in different
locations from one player action to another.  This was true, for
annotated rolls often need the correct half of the pneumatic stack
for their accents, even on instruments without the 'solo' (Themodist)
feature.

My 88-note rolls have stamps which say "Emphasize the Treble Melody"
or "Emphasize the Bass Melody" -- handy on rolls like Scott Joplin's
"Elite Syncopations," which crosses over the division repeatedly.

I use the word "emphasize" since some players will have a 'boost' for
the accents (such as an electric Duo-Art, manually operated, via the
Pianola levers), while most pedal players will 'choke' or 'suppress'
the accompaniment side of the pneumatic stack.  In this way, the focus
is on the musical accents, while the roll interpreter can use whichever
method applies to his/her specific instrument.

Hope that answers your Themodist (scale division) question!

Regards,
Douglas Henderson - Artcraft Music Rolls
Wiscasset, Maine 04578 USA
http://wiscasset.nnei.net/artcraft/