I read the 'First Wave', and thought that Doc Savage might have been used more after that, sadly no. But didn't he get used by Dynamite at some point? I grew up with Kato and the Hornet/Batman '66 in syndication. Vampirella, thankfully was brought back for a bit, and her old adventures were collected by Dynamite as well.
Flash Gordon, and 'Buck' Rogers were favorites in their particular cartoons (Defenders of the Unknown I think?) until I realized that they were older, so I found their serials, and later Armageddon, Buck's story. It's too bad these characters aren't out in the public eye more. As campy as the Flash movie was, along with the cheese fest of Buck Rogers in the 25th C. (Wilma looked great in her body hugging uniform.)
(I see parts of my stories in the 40's with a character, or characters struggling to get used to the tech, as he grew up with tech that could be considered science fiction by those in the era.)
OT: There's an open source character called Air Force 1.0 that I see in different time periods being built with different materials, and having to work around the limitations, if I take the story into that territory.