I would agree with Timmy ..however...
At this stage I wouldn't worry about Type Approval.
I have two UK cars and have never (sic) had any issues - but they are older than yours and no ADRs apply.
The Motor Registry will be interested in three things:
1. Who owns the vehicle?
2. Is stamp duty payable? and
3. Is the car roadworthy (and is it insured)? Is that four??
1. If you can't get/haven't got a receipt from the previous owner, a stat dec will be accepted (BTDT).
2. If you haven't registered the car in NSW previously then you are liable for stamp duty. They all ask you how much its worth and accept any reasonable answer.
3. The Roadworthy Cert. (blue slip in your case because you don't have an existing registration). You will need to find someone with a blue slip qualification and discuss your case with them.
You know the cars build date so read the ADRs and find out which our car is required to meet (all those in force when it was manufactured). You should be able to judge which it will meet. Ask the blue slip guy how he will determine whether it passes. In my experience, "as supplied by the original manufacturer" is generally acceptable - but you should ask.
In my case they wanted proof of age and weight. I used my Heritage cert for age and a Haynes repair manual spec sheet for weight. They would have accepted a certificate from the local (firewood suppliers) weigh bridge.
At this stage you have the "official" answer as to what is required....and hopefully haven't spent any money
WRT your discussions with the local club; I can understand they may not want to accept the liability for inspecting a "new" vehicle but they shouldn't object to things like a second tank. The regulations state the "period modifications" are acceptable and second tanks were commonly done in period......
I find it mildly amusing that it would be pretty hard to find a modification that wasn't done in period. No Honda conversions for sure but the period choices included Jaguar (modified), Chev, Ford (BDAs) so "engine swaps" are definitely period
Cheers, Ian
PS I'm in NSW as well you you should be facing the same regs as I do.....