Heres a picture of a 1942 marked steel tank model next to a 1946, once maroon painted, but it all fell off model. War efficiency and use of war essential materials, a big reduction in the amount of brass used and a simplification of design, both increases rate of production of components, as well as freeing up more war essential brass for making shoot bang fire type ammunition, in 41 to 42 the u boats were sinking a lot of supply ships.
More and bigger ventilation holes, no retaining split pin on pressure release, a change to steel tank, more brass saved, more brass for other essential uses.
For context was war production changes discussion, on which note, painted in traditional service style, oi that man, hands over brush, tin of paint grey, with service pack from airfield stores.
