In all these years, decades actually, never came across anything...but likely, specualation exists. I'll try to snoop around, check old stuff, web also...but would suspect, maybe if something turns out, it may just be speculation. We'll see....even that may be something,or we can invent... heh, heh. Give me some time, and see if any leads your end, also Sgt Tim may have some info. We'll give it a try. Hey..DAN....join us here, maybe you'll come across something.
I have a book...Alex Raymond, His Life and Art. Some of its beginning mentions a few things, but still does not tell all. Seems A.R. was, among other things, most interested in pulps of the day, science fiction, fantasy, adventure authors, along with veteran pulp editor Donald W. Moore. It's possible the latter assisted with scripting FG, Jungle Jim, and AR was earlier involved with Tim Tylers Luck. Seems works from Jules Verne, Edgar Rice Burroughs, and eg When Worlds Collide were certainly inspirational. He was also inspired by looks and prowess of athelete relative Paul Dillon for FG. Artistry of one Franklin Booth also appealed to AR. Perhaps there's more, but I could not pinpoint much for Ming in reasonable amount of time. FG was made though to compete with Buck Rogers.
Interestingly, some time back, I came across material, but not sure percentage if speculation, made up, partial, whatever. Don't recall where or details, but had elements of history, some ancient, in background...also WW1, the Kaiser, Hitler and pre WW2 days, Nazi thinking. These things came out of the minds of men, AR, D.Moore, those who influenced them. Yes, I could likely make up something which makes sense, given time, or possible or frivolous. But, even after reading much..in books, on web, in library, can't really say..much open to interpretation, but we'll still keep alert for tie ins. I do think there is something I left out from years back, I just can't recall now, but it still would not be 100% anyway.
Here's some info. Go to (English) Wikipedia. Type in just like this>.....Mongo (planet).
It leans mostly toward comics rendition, since FG started out moreso as a comic in the media...so, try and follow as best as you can. Of course, we're talking about fictional characters and places, so we're in the speculation/story telling area big time.
Peruse the "stuff" there briefly, then find Witch, Magic, Syk write ups...there is some early story material there for thought. I could bet on it that I saw other "stuff" though fictional, but perhaps with a sense of ancient history eg somewhere on Wikipedia years back. I just don't recall. Perhaps some additional info may surface if that FG movie is ever made. This is best I could come up with for now...but, you never know, check latest editions of the Mongo News from time to time, right here on this forum site.
Certainly a lot of interesting stuff there that I don't recall from the serials. The Magnetic Mountains, for instance, which were featured in the comic strip storyline "The Monsters of Mongo", on June 17, 1934.