Dear Philippe and MMD:  I do have just such a machine and it is
applicable to any music box cylinder.  I built it as part of the work
I am doing developing an historically accurate reproduction music box.

The scanner has two heads: the first heads scan pins, the second head
scans hole locations on cylinders which have had the pins removed
preparatory to re-pinning.

There are advantages to both types of scanning.  Reading the pins
themselves theoretically means that you are able to retain the
information imparted to the cylinder by hand justifying of the pins and
the removal, by the original maker, of pins in any erroneously drilled
holes.  Of course, this also means that the reader will pick up errors
introduced by pins which were bent or broken after leaving the factory.

The hole reader [head] allows for correct reading of damaged cylinders,
but it cannot read any hand corrections to inaccurate or erroneous
holes.  In my limited experience, reading holes gives one a somewhat
clearer rendition of the tunes than reading pins, although I have never
had the opportunity to scan the pins on a truly pristine cylinder.

This machine produces a text file giving the location of every pin
on the cylinder, but I can also produce a MIDI file of the tunes _if_
I know the tuning of the comb.  I produced this machine to aid in the
reproduction of historic movements, so my goal is a corrected file of
pin locations for making new cylinders.  However, I find that generating
a MIDI file of the tune is very useful in determining the pitches of
missing teeth.

I do not know what your interest in this device is, but it can make a
huge difference in reconstructing a lost comb tuning.  Where one or two
teeth are missing there are very few possible combinations of pitches
to try, either by tuning the tooth or by trying out a few chords on the
piano.  Where many teeth are missing, especially consecutive teeth, the
permutations of possible tooth tunings soon become impossible.  However,
if you can listen to the entire piece and change the pitches of
particular teeth quickly and easily (as you can with MIDI), tunings
from badly damaged combs become more recoverable.

Please let me know if you have further questions.  Also, if anyone
would be interested in transcriptions of their cylinders, I would be
glad to discuss this with them and quote a price.

Regards, Jonathan Herz

 [ Jonathan's machine records the _location_ of the pins and/or holes
 [ in the cylinder, thus he can replicate exactly the pinned cylinder.
 [ He approaches the task as does a machinist, and he leaves the musical
 [ aspects as a secondary challenge.  Music rolls and book music should
 [ be archived with the same precision.  -- Robbie