Wikipedia
GAZ–MM is a truck with a maximum usable weight of 1.5 ton was produced at the end of the 1930s and at the first part of the 1940s by GAZ in the Soviet Union. It is a simplified version of Ford Model AA’s Soviet licence version. At the beginning of World War II more than 150,000 were in use at the Red Army.
In fact, GAZ–MM was just a designation of a strengthened 50 HP engine, introduced in 1938, while in factory documents these trucks were still designated as GAZ AA. This name is especially used to describe a simplified wartime model, produced from a beginning of 1942. In some series there were no doors, front brakes, front bumper, front stamped fenders were replaced with plain welded ones, and only one headlight remained. From mid-1942 the trucks had wooden doors, with sliding parts of windows.