Seeing as retrospective law changes are Illegal, But you do live in a Socialist state they probably don't stick to the rules I would research very carefully before cutting any metal.

I would think if you rang the authorities five times you would also get five different answers,I know an Engineer in NSW RMS and he stated the place is now full of Pakistani Uni graduates who used our system to gain residency and they have absolutely no idea what they are doing.
Victoria may be the same so you would find the older Aussie engineers in the system not game to point out the imports don't have a clue but they say nothing because they don't want to lose their Super it really has turned into a Joke in NSW, Victoria may be just the same these days.

Example if building a Hot Rod 32 Ford you cannot use a new build safe strong chassis but as long as you incorporate 30% of the ancient Ford chassis it's pretty much open slather,Pretty dumb when it is supposed to be illegal to actually cut and weld any full chassis and Truck chassis are riveted not welded if modified, So as you can see the Pakistani Import Engineers in NSW RMS are not very bright, Victoria likely has the same issues.