There was a discussion of the film HAPPY PEOPLE on the old blue board last fall, I think the full film (by Warner Herzog) was on Netflix.
Seen in it are quite a few Whirlwinds, several Neptuns and what I think is a Bemepok. There are several members in the USA that have Whirlwinds (also called Vihor or Vortex) I did a write-up on my website about the one I have, here’s the link:
http://www.oddjobmotors.com/whirlwind.htm
These motors are beasts – but rugged beasts since you can see what they need to go through!