I like to remind people, Jack Kirby had no "co-creator" at Marvel Comics because he didn't need one. He did all of that stuff on his own. If you hear anyone saying otherwise, know that you're listening to a liar.
As Kirby was trying to manage his exit from Marvel to places where he could create without having to suffer the indignity of having to see a talentless shill stealing his credit, he was trying (I'm convinced) to lay down some comic book dogma where his creations were concerned.
During this period when he was writing and illustrating the Fantastic Four, he had realized what a truly unique character he had created with the Surfer. And he wanted to establish some further canonical material for the character before he left it in the hands of the men who had so effectively robbed him. There was that much he could try to do as he slowly left the building.
To that end he was using the Silver Surfer off and one during a particular run of the Fantastic Four title. In these stories he was adding to the rich palette he'd already established in earlier stories, crossing his "T"s and dotting the "I"s. These stories are rather quirky, with the Silver Surfer making only fleeting, almost glancing appearances, effecting the flow of the fiction in an almost tangential manner. It was brilliant story-telling that not even an incompetent dialog editor could wreck.
|The mid-grade copy of Fantastic Four #74 that I just picked up.|