Michael, a fan of Grey Gardens recently wrote to Al Maysles, asking about the extra footage not included in Grey Gardens or The Beales of Grey Gardens. The response is vaguely positive!
And, don't forget that the original, pre-raid footage may have resurfaced. Perhaps we'll see that someday too!
From This Very Blog, by Michael Marchello, on February 14, 2011
I have great news! I recently emailed Al Maysles telling him how grateful we are for filming 'Grey Gardens' and the impact it has made on all our lives. I also asked if he planned to make another film along the lines of 'The Beales of Grey Gardens' with the extra footage, and this is what he sent to me:
It's too early to talk about it but there may well be some more Grey Gardens footage to see. But not immediately so please email me often to keep up to date.
Though it might not happen soon, the promise that it will happen at all is enough to keep me excited!