What does ZKO stand for?

[Akira Takiguchi]

I guess it could be a war correspondent related?

Either ... Offizier or ... OST ??

[hucks216]

It could be Zentra-Kraft-Ost which I believe was an organisation set up to take care of vehicle problems in Russia such as provision of spare parts, repair areas, tires, fuel and the salvage of vehicles etc.

[Akira Takiguchi]

Thank you very much! I looked into Tessin vol.1 for abbreviations to no avail, but since now I have a good hint, I may end up with a much better idea of the set!

[Akira Takiguchi]

The same car with a officer, colorwise much better than the previous example.