How familiar was the average literate American with Thor in 1940? There is a story called "The Roaring Trumpet" by L. Sprague De Camp and Fletcher Pratt published in the May 1940 pulp magazine UNKNOWN. The 77 page story lead off the magazine and it featured Thor, Odin, Loki and Heimdall. Pagsilang Rey Isip's comic book, pulp and movie poster art added to the zeitgeist of America for four decades including the Thor painting he did for the UNKNOWN cover.
The interior art for "The Roaring Trumpet" was by Edd Cartier, a prolific artist who is best known for illustrating The Shadow's stories.