Hi Bob,
No it is an American Willies MBT jeep trailer that was bought and used by the Aussies. someone has fitted square guards.
There were many Aust jeep trailer manufactures.
FMC (ford motor co.)
GMH
CH (Charles hope)
Peter's bros
IHC International harvester co.
NSW L/C workshops (don't know anything about these except we found them in the ARN ledgers they are 1942 so type 1 or 2. MORE INFO NEEDED).

There were many USA jeep trailer manufactures but that is another story.
Cheers
Jeff