Indeed, Landrover recognised that the sprockets could be interchanged, and that the signals would be wrong for the respective controllers. If my memory serves me correct, the old camshaft sprocket would only output one pulse per 2 engine revolutions, whereas that latter sprocket was four pulses per 2 engine revolutions (confirmed with RAVE this evening). The later engine (I believe) would be the one that outputs a DTC of P0340 if the wrong cam sensor ring is used.
The main difference between the pre-1999 engine and the post-1999 engine is the engine management computer. Early one is a GEMS controller, whereas the later ECM is a Bosch Motronic (pretty easy to spot from the markings). So that would be a first check, to see if this engine is a genuine 1996 unit or not.
Kim is right about that cam sensor signal though - as well as being twice the frequency of pulses, the Bosch system should have 3 short pulses and one long pulse per two cycles, as this gives the phase of the cylinders for the ignition timing. What you have there seems to be something else altogether. Maybe the "mate" has sourced a third type of pulley?
That is definitely an early crankshaft sensor signal, 36 teeth, rather than the Bosch Motronic 60 teeth (including the missing teeth positions)