Hi Gerd:
Thanks for the extra photos, nice detail shots.
These Kubels were only made in 1934 and 1935 in extremely small numbers.
The early variant is the one with canvas doors and centrally mounted spare wheels.
The later version had the steel doors and spares mounted on the mudguards.
The cross country race shot is really quite interesting.
As a way of getting around the restrictions of the Versailles Treaty, the Germans had to come up with some clever ways to "develop" new military vehicles. In the case of armoured vehicles, they set up a semi-secret arrangement in Russia where they developed and tested tanks etc.
Within Germany, they used the ruse of "cross country races" to both develop new unarmoured vehicles and as well to train the drivers they would eventually need. One can find photos of variants of almost every RW Kubelwagen in racing trim from every manufacturer at these events.
By 1936 or so, Hitler was confident enough in his place in the world that he basically started to ignore the Treaty and the development of both armoured and soft skin vehicles accelerated rapidly and openly. The same for aircraft and ships.
Just a few tidbits.
Bill