yotsuya said:
The problem with evidence is that it is only as good as the truth at the time.

That’s a laughable dodge of reality. Truth isn’t fluid. Uncle George wrote a story outline and several scripts. They weren’t sealed until a date decades later when the truth was to be revealed, they weren’t cryptic, nor were they a puzzle to decode as events unfolded through the years.
Your man isn’t anywhere near that deep. The story he always intended was filmed and released in 1977. What came out years later was also written years later.

There was no profound Original Vision ™ If he had everything planned from the very beginning, he wouldn’t have hired two people to write sequels to the film. The first sequel was a published novel, written in such a way as to make it something they could film. A published sequel, commissioned by and ok’d by Lucas.

he was planning the family drama from the beginning and the earliest drafts of the script bear this out.

“ANNIKIN STARKILLER, a tall, heavy-set boy of eighteen.”
*“LUKE SKYWALKER, Commander of the Aquilaean Starforce. He is a large man, apparently in his early sixties…”
“PRINCESS LEIA, about fourteen years old…”
“DARTH VADER, a tall, grim-looking general…” (age not given)

“the earliest drafts” show nothing of the sort. If you want to truly go back to the very beginning, Vader isn’t part of Star Wars. Two years later all four characters are in the story at the same time, at least two with different surnames. They are not and cannot be related in the the way you wish. No father\son, no twins. It simply isn’t possible.

Lucas has been lying about this for thirty-five years.
The only thing that seems certain about all of this is that Lucas understood that if he continually lied about something long enough some people would eventually believe it, even when the truth is easily discoverable.