Has it been previously registered? If so, it will have had the engineer's report on the conversion and compliance with ADRs before registering. You should be able to prove the previous registration and just get the roadworthy certificate. (NSW paperwork will differ from Victorian which is what my opinions are based on)
If it is it's first Australian registration then it will need an engineers report on the conversion and compliance with ADRs for the 1980 model year and roadworthy certificate.
You will probably also require the import approval papers when presenting the vehicle.
I believe ADRs are applicable for every vehicle made after 1st Jan 1969.
I wait to be corrected.....
