Sting 69,
I have just finished cleaning up my 76 Vette & now have full ACT rego. I have brought literally $1000.00s of dollars of parts, e.g. full front suspension rebuild set, interior carpet kit etc etc.
All parts I got from the States from Ecklers or Corvette Central who are great to deal with and you will find that anyone in Aus are reselling their parts. All you need is a VISA and keep your eye on the exchange rate. Most parts are Air freight direct to your door otherwise they come via US post.
There is no import duty on the parts as they are over 30 yrs old & for private use.
Even with air freight you will not get a better deal and I have never, not received a shipment.
Their catalogue are free & help find/identify the right parts for you. It can also be all done on the Web.