Matt - I'm in basic agreement. The MOW grey scheme was definitely done during the 1940's. I don't know when it started for sure but my research indicates that much was done in the early 1940's. Interesting because it was during the height of WW2 and one would think that paint would be a rationed commodity. However as I type this I recall reading something that the MOW grey was based on navy colors which would be in plentiful supply at that time. I look forward to any corrections to my understanding if necessary.
Dan