Sorry for the thread revival.
I emailed CASA about the original question by the OP.
Here is the response by Miles Harris
Brad
I draw your attention to CAR 1988, Part 1, Para 2 Interpretation, para 7 as follows:
I agree that you are able to carry tools of your trade on board a CASA GA acft for the purposes of conducting a job at your destination. The reward you are receiving is for your professional services required only at the other end of the trip, not for the use of the acft to get yourself there.
Sections (v) and (viii) highlighted is, in my opinion, a hybrid of where you are at wrt your case scenario below and is deemed to be a private operation.
Concerning RA-Aus acft, you would have to approach them, and get there technical advice on this matter. If you wish to present this email to them, I don’t have any issues with this.
Rgds