Its Dave Basham's bike (remember him; he dominated nationally between 1965 and 1973, winning 4 National titles, 2nd twice and 3rd on 5 occassions).
Hopefully some-one would have kept the bike. Freakshow???
TooFastTim is on the money. The crane would have been used to lift one end of the bike to measure the centre of gravity height.
Obviously the South Aussies mx scene was technically very advanced back then, despite their appearance (I wonder if they had to wear hair nets while racing to stop the hair catching in the exposed counter shaft sprocket
).
I think there may have been some nut tightening going on.