Australian Datsun 1200 passenger models do not have a 'compliance plate'. These were not introduced untill the advent of ADR's in the late 70's & the 'compliance plate' was attached in order to certify that the vehicle was built in a certain month & year & that it 'complied' with the relevant ADR's that were applicable at the time of manufacture & these were identified with the relevant number stamped into the plate from behind.

The plate that is being refered to is a manufacturers identification plate & it is stamped with the vehicle chassis number [to ensure that the rest of the data is applicable to that particular chassis], the chassis code, the engine capacity, the power rating & some other basic information.

The standard 1200 has a power rating of 69 HP @ 6,000 rpm. & the 1200 GX produces 83 HP according to the Wiki entry.

As far as I know, the 1200 GX was raced at Bathurst & in order to be legal, it was necessary for 100 examples, identical to the car being raced, to have been registered in Australia at the time of acceptance into the field.

If all of this is true, then this would mean that 100 or more Datsun 1200 GX coupes were sold in Australia.
Because they were sold through dealers into the Australian marketplace, it would be necessary for Nissan Australia to service them with a spare parts supply, & my Australian parts book lists most GX parts. In fact, my 1200 GX cylinder head was purchased new through my local dealer along with the valves, the double valve springs & everything else that was necessary to build a new cylinder head assembly. All of this was available ex-stock, Melbourne.

It does not list the facelift bonnet [the so-called GX hood] as the facelift model was never exported, nor does it include the 5 speed gearbox as this was never an option in export models.
Essentially the 1972 car was retained in production for export markets, including the GX version.

At this time, I am of the opinion that 100, or slightly more, export model Datsun 1200 GX coupes with 4 speed transmissions were released into the Australian market during 1972.

You will need a fair measure of luck to find any of the surviving examples & quite likely a fair swag of cash to secure it.