These early music transcribing systems deserve mention:

- Peter Phillips and Wayne Stahnke, working independently in the
late 1970s, built pneumatic transcribing systems which created
electronic digital data files of Ampico piano rolls.  Ref.
http://www.petersmidi.com/photos.html 

- Teledyne Controls, in the late 1970s, built a piano roll
transcriber system to create the piano roll music library for
their solenoid player system which later was licensed by Marantz
Pianocorder.  Ref. http://www.midiplayertools.com/MIDI%20Players.htm 

- Micro-W Distributing, Inc., of New Jersey, and inventor Louis W.
Ploch developed a piano roll transcribing system in the late 1980s
which converted the QRS master roll library to computer files.
Ref. http://www.secinfo.com/dRqWm.51Jmh.8.htm 

- Mike Ames, with Terry Haughawout and Ron Perry, built mechanical
and optical (photo-transistor) readers to transcribe folding book
music to MIDI files.

Robbie Rhodes
Etiwanda, Calif.