Philip Jamison's music roll may be from a Hupfeld mechanical piano.
The Hupfeld mechanical piano was very similar to the Pianotist, both
being early mechanical pianos with no pneumatics, just a totally
mechanical action.

Both played a roll of thick manila card and, if I remember correctly,
the Pianotist used a friction roller drive whereas the Hupfeld used
a central sprocket drive.  The Hupfeld had 61 notes.  I have inspected
the Pianotist at close quarters but only seen the Hupfeld many years
ago without being able to inspect it closely.

The music roll is read by sprung keys, as in a keyed fairground
organ, and the key movement is then 'amplified' by a clever kicking cam
system.  A rotating felt covered roller extends the full width of the
playing notes above which are held 61 cams on levers.  The key, when
rising through the slot in the music, allows the cam to drop a fraction
onto the roller where it receives a kick, which then causes the note
to play.  The loudness is dependant on the speed of rotation of the
roller.

This system is very crude in its design and does not lend itself to
quality music.  It is, however, a very interesting back alley in the
development of automatic pianos.

The Hupfeld 61-note player was available in a push-up version as
well as built in.  If any reader has one of these, in any condition,
(Pianospiel-Apparat No. 20) I would be interested in buying it!

Even earlier than this was Hupfeld's piano playing apparatus No. 10,
which was a push-up device playing 36-note discs identical to 36-note
Ariston discs.  One of these is shown in detail in Kevin McElhone's
new Organette Book.

Early mechanical pianos can become a subject for collecting in their
own right, as they often contain ingenious mechanical designs.

Kind regards from Great Britain,
Nicholas Simons