Hello everyone.  I believe the MIDI tuba mouthpiece was made by
Thuringer of Eichsfeld, Germany, as an accessory to their 40-note
accordion.  We sold these back around 2008.  The tuba mouthpiece would
go into any brass instrument, even the Alpine Horn which was really
wonderful.

The 40-note accordion can transmit and receive so multiple instruments
could play together and this is what also operates the tuba.  I do
still have one Thuringer 20-note concertina for sale if any one is
interested.  Take a look at http://www.nickelodeonco.com/ or
http://www.nickelodeonco.com/20-note-concertina-midi-for-sale.html 

All the best,
Ron Schmuck - The Great Canadian Nickelodeon Co. Ltd.
http://www.nickelodeonco.com/ 
nickelodeonco@gmail.com.geentroep [delete ".geentroep" to reply]