All I could find was...
The prop 10-cent "CREEPSHOW" comic book featured in the film was drawn and inked by veteran artist Jack Kamen, one of the artists for the original E.C. crime and horror comics of the 1950's. Creepshow was a tribute to these comic books. Jack Kamen also created the comic book-style poster for the film, which was also featured on the front of the Plume "Creepshow" comic book adaptation (which Bernie Wrightson, another prolific horror comic artist, drew and inked the interiors for). Originally, (Stephen King wanted Graham Ingels, another EC artist (famous for his work on the title "The Haunt of Fear") to do the artwork for the film's poster, but he refused. It was head of EC comics William M. Gaines who then suggested Jack Kamen do the assignment. Kamen accepted.
Wow talk about a scarce book! Great job of research.