Having spent rather a lot of time on this one, I can add a bit of detail to the puzzle.
The puzzle car is indeed a Mercedes Benz G5 "Kolonialwagen" or "Jagdwagen", both terms were used.
As far as I have gotten in the research on this one, it was a one off for the British Motor Show of 1938 and was intended to promote interest on the part of Britain and the Empire countries, hence the right hand drive. By the time of the Show, Germany's intentions for the future of Europe were becoming rather clear and the car was not very popular and certainly was not going to be a commercial success. I do not know yet what became of this particular version of the G5.
Of note, during roughly the same time as a version of this car was gifted to the President of Czechoslovakia by Hermann Göring, other Mercedes cars, primarily the 6 wheel G4, were being gifted to amongst others, Mussolini, Franco of Spain, Haile Selassie of Ethopia, the King of Greece, Farouk of Egypt and Marshall Mannerheim of Finland.
Here is a photo of the car of the Czech President, which is essentially a civilianized version of the military G5.
Bill