Ausco,
Desert Phantoms had larger tank, slightly wider ratio gearbox (1st gear was slightly lower), longer piston skirt for milder inlet duration & heavier flywheel (I think). May have had lower compression ratio as well. Some models had vertical rear shocks also for more rear travel.
Evo, there was a black model "Six Day" (not SDR) in late 70s/early 80s which was pretty much a desert phantom w up-pipe