Twotees is spot on regarding removal of ADR plate and putting on another body being not lawful in NSW. Not sure about other States. Would it stop me? No it wouldn't. I'd still repair the vehicle (front cut, cowl repair etc). I'd still buy a good 1-tonner cab and put it onto another chassis, and put the chassis's ID plates onto the cab.

When it really came down to it, the legal identity on a HQ-HZ is the rails and plates. So in theory, and in compliance with the rules showing how stupid the rules are, one way to perform a body swap is to use the whole cowl section off the original car complete with ID plates on another shell, and then put that shell on the chassis that matches the ID plates. Stupid? Yes. You never interfered with or tampered with the plates. To me this means the rules are there to primarily stop rebirthing (ie stolen car made legitimate) and fraud (GT Falcon owners primarily are the most precious locals about this). Repairing a car you own with parts was probably never the main intention of any of these rules.

And this quote is spot on too:

You may get away with for now but in the future, if you sell your vehicle as genuine it might just come back and bite you and remove a large wad of cash from your bank balance. Check out the unique cars magazine article from a few months back.

It all comes down to how you advertise and sell the vehicle if you choose to sell it. That court case was civil, not criminal.