Hi Philiphardaker, It looks like either a 1947/1948 Dodge or a 1947/1948 Plymouth. The rear looks the same as they share the same body. They were tough old buses and popular in the bush before Holdens started to own the market as a Holden was a fair bit cheaper. Its likely a 4 door as the 2 doors were not built in South Australia and imports were few at that time. I've added a couple of photos that I found of ones for sale on the web.