Pretty sure that's a Chevy Blitz cab, not a Bedford Blitz.
Most probably a Chevy C15A No. 13 cab , lots were imported in Australia from Canada during WW2 , some were made locally and used the name Bedford ( UK )
I stand corrected!
Just to throw a spanner in the works, I'm pretty this is a Ford Blitz!
Chev and Ford supplied these to the Australian Army in WW2 , I'll put it down as a CMP Blitz