Update: Tunehouse looked into the problem and identified a wiring issue between the camera unit and the connector. They managed to get it working , but did warn me at some point it will stop working again. From their perspective it is unserviceable and will need replacement.
They did some research and found that the new replacement camera would be Approx $1400 supply only (their fitting cost would be $190) . They did provide the part number (28442-JL05B) and a quick google of the part number shows that these are rather expensive brand new (seemingly no longer in manufacture) for the places that still have them in stock, with the used option potentially presenting the same issue down the track at some unknown point. They are happy for me to supply the part so that they can fit it. Decisions, decisions...
I can definitely recommend Tunehouse (thankyou Vee37!). Cost for the diagnosis was as quoted ($190) , car was ready on time and communication was top notch. Their workshop is super clean and modern, and there was plenty of car candy parked out the front on the day I went. Would definitely go back.