RE: x-rotation ?
I have done some more research and now am convinced that the radio controlled (untethered) helicopter described in this thread is really an XRB Lama tethered model in disguise. I've found extensive parts lists for the Lama and they look absolutely identical (except for the bits relating to tethered vs untethered such as the battery holder).
I've ordered some Lama parts to prove it and I'll get back to you later with a definitive answer.