Let's take a look at some maps. The early maps from Mid-Continent were pretty decorative and stylish, but in the 40s, they began to get fairly plain and not nearly as exciting as from some other companies.
This is the oldest example I've seen, from the very early 30s, 1931 or 32:
This was the next mpa, from 1833 (+/-) Definitely my favorite.
Nexct came these two from the mid-30s.