From memory: a model in scale 1:20 had been ordered during the early stages of planning and production. In the 1930ies, Heereswaffenamt WaPrüf 6 had a model of the K-Wagen. However, even at that time is was uncertain whether this was the WW1 model or where else it had come from. The pictures were taken from that model at WaPrüf 6.
