I'm afraid such car body finish would be impossible way back then, my friend. Acrylic paint and lacquer weren't yet known in the late thirties of the last century. Soviet cars used to be black then, pretty much like German Opels. Later on the Soviet makes of personal cars used to be predominantly dull gray until the Soviets bought that Italian Fiat car factory and started to produce their "own" cars called
Zhigouli (better known to you under the brand name
Lada). The color of those cars varied from plain white and red to blue, but never black. My own, the first one ever, looked pretty much like this, and it was of this particular color called "linden green":
P.S. And the ZIS tarpaulin would most likely be impregnated with dark rubber for better weather resistance.
