This is hugely helpful, thank you very much. This lines up with what I've been researching
The only thing I'm having a hard time with is the timeline for the Christmas Special cartoon. Its a rewrite of issues #11-16 of the Marvel Star Wars comic, but the last of those weren't released until July of '78. I have found where Marvel originally submitted the comic ideas to the Lucas team for approval, so I suspect the early comic book approval submissions were repurposed for storyboards for the Holiday Special cartoon. It appears the Lucas team bundled up the SuperTrooper concept art as a reference for Fett, added in the name, and then the Nelvana cartoon team went from there. I can't find any dates on the production of that cartoon, though.