Hey mcoates and catseye,
Thank you both for your info.
I have heard back from Tangalooma Resort, who own the Tangalooma strip. As mentioned prior - they usually only consider giving permission to resort guests, but after some back and forth they would consider my request. Here's what they said after my request went to the directors:
Unfortunately I have just heard back from one of our directors and the airstrip is not in a usable condition for a fixed wing aircraft at the moment, or for the next couple of months.
There is an alternate landing strip at Kooringal through Kooringal Oyster Farms that could potentially be used.
I will drop Kooringal Oyster Farms a line. @catseye did you fly in or out of there, or just suss it out on the ground?