One of my favorite things about Em pinball is all the great artwork. Back then many companies were producing a game or more a month. There had to be a fair amount of pressure for some of the artists to keep cranking out something original.
George Molentin is one of my all time favorites but he must have been under the gun on the backglass for Williams 1957 Arrowhead. Compare it to George Petty's calendar page from 1955. Petty was a prolific pin-up and advertising artist in the 1920s to 1950s. Maybe they knew each other and collaborated on it? I just thought it was interesting and maybe you have seen something similar.
Alex