I'll second that, Steve! And you're right, MM #3 does look heavily pulp inspired.
In fact, it wouldn't surprise me if Alex borrowed elements from a horror pulp cover to create this...
Maybe someone with a broader knowledge of late 30's horror/crime pulps can find a direct link.
I'd love to see the pulp cover art that inspired this macabre beauty!
As always Cat, your books are just amazing! Man, A legless guy wielding a hatchet with skulls and an evil Buddha robot in the background! Schomburg rules!