I just came across an article in the Feb 1, 2013 issue of The Atlantic magazine on Margaret Brundage, with cover illustrations from Weird Tales. Thought you might like it as well.
See http://www.theatlantic.com/entertainment/archive/2013/01/the-revenge-of-margaret-brundage-the-queen-of-the-pulps/272715/ for the full article and information about a forthcoming book on her.