I agree, Belgium is most likely - especially since the Germans must have captured at least several dozens of 1-ton Ford/Marmon-Herrington chassis/cowls which had not been converted when the Germans invaded - see the thread
Mystery Fords?
I like Nuyt's "ignorant" suggestion, though! From 1937-1939, Ford Köln sold V8-51 trucks to the Wehrmacht, and by 1938 General Schell, Director of Motorisation for the Wehrmacht, introduced a far-sighted plan to cut back on the numerous different makes of commercially-based vehicles in service. The Schell-Programm proposed to procure just a few standard chassis. This was both a threat and an opportunity for Ford Köln. If this is a factory-fresh 1939 model Ford-Marmon/Herrington, it could very well have been Ford Köln's proposal for the
Mittlerer Personenkraftwagen (Medium Personnel Car) class. All that Reinhard Frank knows about it is that it "was tested extensively in Köln, Germany". Like Ford, Marmon-Herrington was selling their products all over the world to anyone willing to pay, so why not to Germany?
In the end, however, Horch (Auto-Union) was to build the Einheits programme vehicles in the medium chassis class, and they were also the main builders of the Einheits programme heavy chassis cars. Possibly as a recognition of their efforts, Ford Köln got a contract for some 2000 examples of the
Schwerer Einheits Personenkraftwagen during 1939-1941 (when the Einheits models were pahsed out of manufacture). Ford Köln's s.E.Pkw was a built exactly as designed by Horch, except for fitting their own 3.6 litre 78 hp. V8 engine. And they were the first and last 4x4 vehicles built by Ford Köln during WW2.
I think we're onto something, aren't we?!?
H.