Well I have the truck already under construction and I have several Tamiya cook wagons so I guess I am good to go on this one.
I’m not saying this was never done, but I have photos of the installation of a “Gulaschkanone” in the rear of a 3ton Opel Blitz, which I used as inspiration to produce a similar model. As far as could be seen, the installation was a field modification, the wheels being removed and a sub-frame to support the field kitchen fabricated from angle iron, which I would propose as more likely. The photo had the truck marked on the side as “Kuche”, implying the conversion was pretty much permanent. As well as the wheels illustrated and supplied, the standard field kitchen could also be supplied with pneumatic tyres on wheels similar to the Pak36 to be towed by a motor vehicle. Photos of these are rare, but I have seen some. For motorised units this option was more likely, but of course putting it in the back of the lorry made the outfit more flexible.