Jim Walker Firecracker

Anyone ever see one of these fly (or maybe flown one yourself)?  Seems like a pretty crazy setup - you hold a squeeze bulb on the control handle that supplies pneumatic pressure through a long tube to a bellows at the engine, which then swivels baffles in the exhaust and the air intake to control engine speed.  I can't imagine trying to somehow work this effectively while flying ... and that rig!  A flex-tube somehow sent down along the whole length of the control line?  Good luck with that!!! I don't know, maybe I'm wrong and it all worked great - at least must have worked well enough for Jim Walker to mass produce?

I love these kinds of things - pretty interesting in any case.  Unfortunately the squeeze bulb rubber has dried out and the bellows top is gone, but otherwise it is complete and in great shape!

I'd like to hear any other history on this engine if you know it. Thanks in advance!

Tim