This is a screenshot from the Making of ESB. This is the vintage papers for his treatment for the sequels, circa 1977 or 1978.

And yes, I'm serious. I took that image from Rinzler's sw.com blog.

It's the same as the prequels. He said he had full treatments for 1,2 and 3 since the 70s. His company even said on some occassions he had scripts. But then ten years ago he admitted all his 'treatments' were was some pages of unordered notes.

He no doubt has these for the sequels as well, because he was considering them in the late 1970s and early 1980s. But his actual "treatments" to both seem to just have been him writing "episodes 1,2 3" and "episodes 7,8,9" (and also at one point 10,11,12 as the above shows), on a pad of paper and going to bed. These are the closest to prequel and sequel treatments that have been unearthed so far.

However, given that the first new film is a mere three years away, I am sure Lucas has by now ACTUALLY created treatments, which probably incorporate some of his original notes. However, I don't believe he ever had at any point full, proper story treatments prior to this, especially since he seemed to genuinely believe that there wasn't much story material beyond Episode VI only a few years ago.