Another character who seems to be based on Fawcett's Captain Marvel is Marvel's Captain Mar-Vell. Maybe not at first, but later, the way he ended up sharing his existence with Rick Jones, having to swap in and out of the real world, seemed very much like they were trying to bring the character more in line with being a more sophisticated version of his old namesake. (Roy Thomas, who was writing Marvel's Marv at the time, is a well-known fan of those oldie comics.)
Very good point, Gary.
Mar-Vell was so much like Superman in many ways. His name had the Kryptonian hyphenated convention. He came from a high-gravity world like Superman did. His later costume was the classic red-and-blue that Superman made ubiquitous for super-heroes. He later had powers partly derived from converted solar radiation. His race, the Kree, seems to be a derivative of Krypton/Kryptonians, and they're similarly ultra-advanced like the Kryptonians were.
I'd say Mar-Vell had more in common with Superman himself than Captain Marvel.