Background: Science fiction short story (pulp, 3 pages?) circa mid-1950s/early-1960s. This is NOT a television episode. It is a paper and ink tale with a TV art designer protagonist.
When I was a boy, there was an short story about someone (think Syd Mead or ‘Matt’ Jefferies of Star Trek, but this story was way before than ‘Trek) who was so good at imagining the future that the TV actors on an series he was supplying with concepts, props, and sets behaved as if they’d been marooned in the 1800s.
I don’t how the beginning started but in the last few paragraphs, two ‘government employees’ were aliens. (One of them didn’t know what ‘FBI’ meant ‘federal agents’.) The artist’s work was too real as the time a prophetic science fiction story was too accurate about how to build an atomic bomb. The ‘government employees’ were interested his graphic design. In the final sentence, the protagonist found out the flying saucer on the yard.
No idea about the first drawing, but the second illustration is burned into my memory: The art director’s office was filled with appropriate paraphernalia, desk clutter, etc. It was supposed to be a 2/3 configuration of a cutaway spaceship. As I recall, there was a mistake visible in that model: a spaceman (the word ‘astronaut’ hadn’t been invented) in his pressure suit, ‘floating’ on an umbilical, INSIDE the hull.