Phil
My neighbour down the road owns a civilian 4X2 version of that truck, known as LODESTAR I think - the cab on it would be same or similar as your K9 DOG truck, probably .
The CFA ( Country fire Authority ) here had a fleet of Austin tankers from the 50's , based on that model . I remember them being sold very cheap during the 80's... they have all dissapeared it seems.
Here is one in NZ
http://www.flickr.com/photos/23210521@N03/2942779124/
Mike