Looking at the REMLR.com website (look under ARN - Army registration numbers - listed by Chassis Numbers), the vehicle is not ex Aust Army and is also not listed in the "imported" list lower on the page.
So you vehicle is either a private import from the UK or one of the 101s that were brought in from Brunei quite a few years ago.
You should have a plate in the passenger wheel well - that lists all the original numbers.
Cheers
Garry

