Pete, Richard,
thanx for your replies, so we can assume the truck being in fact a Leyland Retriever.
Unfortunately I have no other pics of the car at that location.
That's what I found at Bart Vanderveen, ...

...with the radiator cap at the "wrong" position.
Please tell me, where can I find further info on the truck ?
I'd really love to add it to the site...
Regards,
Oliver.