As a retired intelligence analyst and having done a reasonable amount of historical research on K&C’s Arnhem ’44, Market Garden and Napoleonic Gordon Highlanders series, I was curious as a result of the forum discussion regarding the forthcoming FW092 “Kaiser Bill’s Staffwagen”. Here are the first cut results of my research. There is a book entitled, MILITARY TRANSPORT OF WORLD WAR I, including vintage vehicles and post war models, C. Ellis and D. Bishop, Blandford Press Ltd., London, 1970 (also MacMillan Co. in the USA), Lib of Congress Card No. 71-124874. Perhaps other members of the forum may have the same reference in their library.
Plate 33 in the book is captioned NAG 4-ton Lorry, Military Subvention Type, 1909-12, Germany. The truck chassis is basically identical (down to several small details) to the K&C “Staffwagen” with the following exceptions; 1) Set of headlights mounted adjacent to the engine bonnet (hood), 2) Steering wheel and hand brake lever on right hand side, 3) Larger rear wheels with drive belts (not chains) coming off transmission feed spindles which are further forward on each side of the chassis, 4) Hand crank for starting in center below radiator, 5) What appear to be all four solid rubber tires and 6) Upright engine exhaust pipe on right hand side of driver's compartment.
The depicted configuration is a cargo truck with a canvas canopy over the wooden bed (with wooden sides), and folding canvas cover over the driver's compartment. Would be a fair conclusion that the drawing in the book may well have served as at least one reference source.
Can neither confirm or deny (that's intelligence speak) the authenticity of any further specific application/modification incorporated in the "Staffwagen" model.
Would suggest interested forum members may want to Google search the above cited caption for possible additional information. Hope this helps.
Best regards for a Happy, Healthy and Prosperous New Year,
Arnhemjim