One of my favorite podcasts, 15 Minutes With [Mark] Waid, has a new episode discussing Secret Origins #46 (1989), the story of Fortress Lad. Yes, the Legion of Super-Heroes headquarters at one point was a person. Eww.
As Waid puts it, “there’s an origin to this origin story,” and he tells it — why this issue was all about superhero headquarters, what the story was originally intended to be and why it was replaced. Originally, Gerard Jones and Kurt Schaffenberger did a story about the rocketship the LSH hung out in that was very very different, but since Superboy wasn’t allowed to be connected to the Legion at that point, it had to be changed.
KC comes in because he was working at DC at the time and threw out an idea that became the replacement story, since they needed 12 pages quickly. Thus, Fortress Lad, with art by Curt Swan and Ty Templeton. (If you don’t know the story, Waid tells it, so go listen.)
That story, by the way, was also the first appearance of Arm-Fall-Off Boy.