The closest contender to Supersnipe for self-reflective comic book series of the Golden Age of Comics was the “Comics” McCormick feature, which ran for about half-a-dozen issues of TERRIFIC COMICS (“Loaded with Action!”) beginning in 1944.
“Comics” McCormick was the brainchild of Ed Wheelan, a former newspaper strip artist who had originated the Minute Movies feature. He eventually brought Minute Movies over to the pages of All-American’s FLASH COMICS after it had run its course in the newspapers, and over the years he gradually branched out to doing otter things as well.
Like Supersnipe, McCormick had subsisted on a steady diet of comic books, and like Supersnipe this caused him to have vivid Walter Mitty-esque fantasies in his daily life. He never adopted a home-grown union suit as Supersnipe did, at least outside of his imagination, but otherwise the two characters were amazingly similar. Were they ever to meet, I’m sure they would have gotten along.
It’s a product of the era that Comics’ mother worked in the local defense plant making weapons for the war effort. Presumably his dad was away in the thick of the fighting.