It's often said that Roddenberry chose the name "Khan Noonien Singh", and later "Noonien Soong", as an attempt at reuniting with a pilot he became friends with in WW2, with different stories saying it was someone named Kim Noonien Singh or Noonien Wang. But I've never seen a source for this, or even a quote from Roddenberry about it, just a bunch of places mentioning it as a factoid.
"Noonien" doesn't seem to be an actual name though, so far as I can tell? Every reference to it I can find is to Khan or Soong. Additionally, every source I've ever seen for it has been post-TNG, never anything more contemporary like an anecdote he shared on the 70s convention circuit, or behind-the-scenes books from the time like Making of Star Trek, or even fans just mentioning it in any of the "Trek" magazine compilations. Plus, the choice of character in Khan has always made the specific story just ring false to me. Or at least that it might just be a telephone game thing. The name did carry through all the later episode edits as Khan's name was settling down into its final form, and Roddenberry did push back against the studio to insist it be part of the character's name, so I can believe he got it from somewhere? But the details of the story just never really hung together to me.
Do we have any actual quotes from Roddenberry himself about this anecdote, or any sources from before TNG that confirm it was the source of Khan's name? What's the oldest source we have for it?
