G'day Ausmv,
That looks like an ex RAF ambulance to me originally from the UK.
The ambulance body was built by Marshalls of Cambridge, a famous defence contractor who did a lot of work for the RAF over the years.
The British army had them as well, but the crash rescue plate points to the RAF.
If you search the web for something like Series 2A ambulance Marshalls, there is lots of info.
As for how it got here, a lot of them were converted to campers after they were sold off, so maybe someone brought it out here on a big trip.
Looks like it needs a bit of TLC, and it may not be in its original paint!
Cheers,
Mike.
