outofwhak,
that's an very interesting hint thank you. I will do further research on this!
As long as you are operating the VH aircraft in a ICAO contracting state then our CAR 42ZD 2b applies
2) A person may carry out maintenance on an Australian aircraft outside Australian territory if:
B. if the aircraft is in a Contracting State--the person would be permitted under the law of the Contracting State to carry out the maintenance if the aircraft were registered in the Contracting state
And no special permit required from either country.... For private ops at least.