Ola Guys
Thanks for thinking along with me.. It really is a puzzler I have a lot of pictures of the Pak36 and a fair amount of them are with vehicles and I have not found a single one in my pictures that matches this truck.
@ Frenchi
Far fetched as it might seem. It indeed seems to match the wheelhubs and even the front fender just visible in front of the sparewheel seems to be fitting. However. Again if it is this truck they did some big rebuilding of the truckbed and fenders on the back.
@ Matthew
I'll have to do some research into that type of Adler. The pic is not clear enough to determine if the truckbed is similar but the quick search I did make it look like a contender as well.
@ Roger
I have several pics of wanderer kubels towing the Pak36 and they are close but not really close if you get what I mean.
@ Lars and Chris
I'm not convinced it is a Steyr 640 either and I'm convinced as well it is a 2 axle truck since there is wash from only 1 wheel visible under the cargobed. It was the width that at first ade me think it could be a lend lease Dodge but that doesn't explain how it got a civilian licenseplate.
@ Henk
Sadly this is one of the pictures in my collection that is not written on the back. (Zal je net zien

) so yeah that makes dating this pic very hard. You pretty much summed up what I think about this pic as well and it is a strange vehicle. Actually Cliff (MrRoo) had quite a good theory about the crescent shape cutout at the back. With it being a modification by the crew to get in and out easier when the gun is attached to the vehicle.
I know there are lists of numberplates online and which vehicles they belong to as far as can be determined maybe I can find a hint there.
the search goes on.