The Höffle 20-key crank organ is growing in popularity.  Many people
have already made a self-built crank organ based on the plans of
Walter Höffle.  An example can be found and heard on YouTube --
http://www.youtube.com/watch?v=FuAL6LPer4s
 

The plans are available on www.hobbydraaiorgel.nl (English pages
included).  You can get there free MIDI files too for this organ.

With kind regards,
Wiel Geraats
http://www.hobbydraaiorgel.nl/