Right! Here’s a turn up for the books! It appears to be LHD ERF KV with a Spanish built sleeper cab.
Here’s a reminder of what its British counterpart looked like.
I was tempted to think that the Spanish were ahead of the game with the sleeper cab, until I remembered that ERF did buid this crew cab version of it 
Did the MOD ever buy any ERF’s (prior to the takeover by MAN obviously)? If so, I don’t think I’ve ever seen any pics.
The only one’s I can think of are the four- and six-wheel rigid ERF C1.4s and C1.5s that were built for the Ministry of Supply in WW2. They mostly served in France and North Africa. Many were fitted with 7.7 litre AEC engines. Apparently they performed very well but the front axles broke in rough desert terrain (North Africa). I can’t remember seeing anything post-war though.
EDIT to add pic from 60 Years On - The Story of ERF
SPOILER ALERT! Tongue-in-cheek provocative post coming up…
Here is a nice ERF starting up on a cold morning:
And here are two nice (contemporary with the ERF) Volvos starting up on a cold morning:
Which all goes to show how quickly we forget the details, and that they were all as bad as each other in those days - well, the Volvos look worse! 
Cold, still, Monday mornings always had a a cloud of blue smoke over the yard. A dozen Gardners, assorted Cummins and Leylands all contributing.
This in a different class though:
I’ll bet the local Halfords ran of Easystart that morning
Ps is the Birmingham Sulzer behind it jump-starting it? 
It’s KFH 248P, one of a pair of ERF NGCs. They ended their days with Trans Arabia in Jeddah.
Interior shot of an ERF ECT. I thought they were really good trucks to drive, but completely spoilt by the inane Comfortshift gear change. It was a Cummins-engined MAN in the end of course.
Here’s the last one I drove:
