Misc info on the B25s
The Russians used C,D,H and J models. They were not used much for close air support. The A20 was better for that. They were used for long range strikes against airfield and supply points and movement routes including bridges and rail heads. From what I read, the B25 were used for night bombing. It was common the put a fuel cell in the bomb bay and mount small bombs on the wing. Lots of straffing. After testing, the H models went to the navy. The army did not like to cannon. Several models were also used for anti shipping and armed with a torpedo.
Many of the C models had cannons installed in the tail. D models were modified in Kanas City, the waist guns were added. There was no standard arming of the plane. Some had a single MG in the nose, a flexible and one or two fixed forward firing. Some had two or four gun packs added to the nose. The Russian replaced the bomb winches with the own heavy duty models and would use bombs from the US, Russia and Germany.
The Russian used 5 man crews instead of 6. The navigator was moved into the nose and also released the bombs. The Russinas crew loved the plane because it was big, the heaters worked and it was modern.
At first the Russian fuel would eat through the fuel cells and American fuel had to be shipped in 55 gallon cans to the airfields.
DBII