The map was published by H.M. Gousha Company (H.M.G. Co. in lower left corner) in 1940.  They printed city street maps at that time, and for about 50 years.  Shell Oil (by Gousha), Thomas Bros., and Rand McNally were printing area maps then, but this is Gousha's. But it is on the American Roads Forum -- Donn Dufford '63