Wow, now that was a light read, and damn confusing to say the least....
Don't get me wrong... Hmm.... but it seems to me that under Clause 4 (a), if the car does not comply with the ADR requirements in the first instance, then its exempt?
Have a look.. I don't believe a factory standard 1972 Corvette would comply with ADR Rules....
4 Non-application of Schedule-Motor Vehicle Standards Act approvals
A provision of Parts 2 to 10 does not apply to a vehicle if:
(a) the vehicle does not comply with a requirement of an ADR applying to that vehicle, and
(b) the provision of this Schedule corresponds to the requirement of the ADR, and
(c) despite the non-compliance, approval has been given, under subsection 10A (2) or (3) of the Motor Vehicle Standards Act 1989 of the Commonwealth, to place identification plates on vehicles of that type, and
(d) the vehicle complies with the approval conditions (if any).
Note : Section 10A (2) of the Motor Vehicle Standards Act 1989 of the Commonwealth deals with vehicles that do not comply with an ADR, but the non-compliance is only in minor and inconsequential respects.
Section 10A (3) of that Act deals with vehicles that do not comply with an ADR and the non-compliance is not minor and inconsequential, but the Minister responsible for that Act is satisfied that vehicles of that type comply with the national standards to an extent that makes them suitable for supply to the market.