And thanks for the reply. According to the online reference material, it was indeed Nelson Bridwell who wrote this. You can see how it could have worked as a Super-Friends or Shazam! story just a few years later, but it doesn't quite work here.
Funny how it works, though, with the archetypal history and continuity minded fan-turned-pro writing for an editor who hated catering to hardcore fans or preserving continuity: it was bound to come out badly!