I think that he probably had treatments for these in some form or another back in the early eighties at the latest.

Mark Hamill's comments in a 1983 interview confirmed that GL was at least considering an EP VII and had a story in mind. And Dale Pollack wrote in his book that GL let him read the treatments for all of the sequels, including 7-12:

“It was originally a 12-part saga. The three most exciting stories were 7, 8 and 9. They had propulsive action, really interesting new worlds, new characters. I remember thinking, ‘I want to see these 3 movies."

Now whether or not these treatments are still relevant or will have any impact on EP VII is yet to be determined.