Not the first time the Tas Govt engaged in a bit of nepotism.
I may not have the details absolutely right but for the state mapping contract one had to have a super accurate and very expensive compass that would read off in 1/10 of a degree... to allow for “accurate” photo flight line tracking. Know anyone who can maintain a track with an aircraft in lumpy conditions , or at any time for that matter.
Obviously other companies never bothered, you may not win the contact anyway, and with the normal way of doing things in those days ...Mk 1 eyeball and map reading the PhotoNav directed the pilot for any minor heading changes to stay on track.
Once GPS came along it was a doddle for very small heading adjustments to stay on the invisible track.