G'day Folks
I would suggest it is a Simca (SUMB)MH600BS a French vehicle of 1964 on vintage fitted with a V8 petrol of 4184cc the French version of a Styer
cheers
Good grief, the British Army using an obsolete French truck? Definitely a no no! It is a Pinzgauer built in the UK by a subsiduary of British Aerospace.