The boxes were mostly in military factories. The rest did it themselves. It was just stupid in the USSR to pay money for what you can do yourself. Here are the military boxes.
With JSC "Kamov" (ex. Kamov Design Bureau, Ukhtomsky Helicopter Plant) WHERE WAS the work of THE MILITARY. HELICOPTERS... THE TROLLEY CONSISTS OF TWO COMPARTMENTS, THE MAIN ONE AND THE UPPER ONE, WHICH WERE TRANSPORTED TO THE PLACE
I think it's still snap on. Since there were a lot of deliveries to the Second World War under Lend Lease.the industry of the USSR did not produce anything similar at that time.