Landing without permission will mean that your insurance will more than likely be invalid, and you can be charged with trespass.
How typically Australian, let's chuck up some fear.
they prefer six weeks notice
How typically Australian. Hey we got an airport but ya can't use it without jumping through hoops. Even when you do there will be "terms and conditions". FFS what is this joint? It's nothing more than a derelict piece of Australian history and there is no good reason why itinerant aircraft should not be able to visit.