Ths really takes me back, I donated a Massey Ferguson 35 Tractor yonks ago to the Help Africa cause, Gordon Bennett I would recognise that sound anywhere, along with the tick, tick of the difff that was missing the tops off a few teeth, however me thinks this is just a mock up testing out the design for the pilot would have to sit near to the rotor drive to balance things out, so I am convinced this is meerly a test bench ready for the Mark 2.......
Peter R-B