Unless flying was supplementary to a primary job as Station Hand/Jackaroo, and you were not the owner/pilot, it could well be aerial work. I think the insurance requirement may also get you. Some station flying involves aerial mustering and that is definitely not a task for an hour building PPL, even with a rating.
Large agricultural companies had flying operations 20 something years ago but they have largely disappeared. You will find the odd station owner/pilot.
Stick to your CPL studies.