Hello, Christian,  I am pleased to send a reply about your piano.
I fondly recall the talk you gave at the previous MBSI meeting and our
brief talk afterwards.  It was an excellent presentation and was quite
useful while viewing other book playing pianos since then.

At the last MBSI convention mart, there was a very similar barrel
piano.  It was bought by a fellow from the Midwest, and my friend
Jeff* and I conserved and restored it for him.

You can tell with some certainty about whether it was actually carried
on the grinder's back by looking at the brass fitting on the back of
the piano.  These pianos usually have 2 strap brackets near the top
center of the back, mounted at a slight angle from the horizontal.
There is also a bracket between them to accept a pole which supports
the piano while it is being played.  Straps would go from these 2
brackets, over the shoulders of the grinder, and then under his arms
to 2 more brackets on the bottom of the piano (at each side).

I suspect that the reason that your instrument plays Turkish tunes is
the tuning and lack of barrel registration.  If these instruments are
not in tune and properly adjusted, it is amazing how terrible they
sound -- to the point of making the music totally unrecognizable.
Although the front looks a bit strange, the rest of the instrument
looks like a typical English barrel piano.

Be very careful about tuning the instrument.  It is very easy to break
the wires by over tensioning them.  These instruments were tuned to a
much lower scale than the current 440 Hz standard.  I'd suggest that
you take a chart of the current tuning and make the smallest adjustments
possible to bring it to relative tune (the strings in tune with each
other but transposed to a lower scale).  Usually the tuning is written
right on the pin block but if you tune it to these notes to match a
piano, you will surely ruin the instrument and possibly injure yourself.
If you are going to do this, send me a note and I'll explain what I
mean.

If you have other questions, please let me know.

Regards,
Craig Smith
near Rochester, New York USA

* My friend Jeff is one of the very few people who can tune and adjust
a barrel piano so that it actually sounds pleasant.  Most barrel pianos
that I've heard would make the skin crawl right up your back.