The organ at Kassel St Martin by Rieger Orgelbau
https://www.youtube.com/watch?v=LQEJ18d0tms
is based on demonstrations heard at the 2011 Zurich symposium
https://www.youtube.com/watch?v=JxhgZObqlLw
https://www.youtube.com/watch?v=CRmLHvtHruk
Best wishes
David P