Basically, you've embarked on a "project", the progress and outcome of which will be interesting but academic to the vast majority of us here.
Imaging the HDD is a neat idea, although experience of HDR-FOX suggests it would be possible to just bung in a replacement HDD and format it. None of the HDR-FOX's operational stuff is stored on the HDD, only recordings, timeshift buffer, etc. The hitch will be if you can't open the box (minor damage won't matter if you have no intention of claiming warranty, although it will affect resale value).
Compatibility is not just a question of the digital encoding of the broadcast stream. Choosing your country in the initial set-up is not only about language, but also configures the tuning frequency range, channel spacing, audio subcarrier, EPG system, and such. Each country's broadcast system has had to evolve from completely independent origins rooted in history, because of the requirements for continuity. It is not possible to rip it up and start again, because of the installed user base and other users of the radio spectrum. I also think there is a bit of protectionism for local manufacturers.
In particular: the UK uses a 9MHz channel spacing, whereas background reading indicates Australia is 7MHz. Therefore, when you scan for channels using UK settings in Australia, it might only find those which happen to be coincident with UK frequencies. That's why it was mentioned earlier in the thread you might be better off with system settings for Germany. Martin Liddle's post above suggests there are no user configurable country settings on the Aura, which indicates the settings might somehow auto-configure, or maybe they are preset for the country of sale.
By diving in before discussing it, you've taken a gamble.