The photo above was posted two days ago on the Twitter page of StarWars7783. The photo was taken in late 1979, and everybody looks pretty happy. Seated at the table (or squatting), from left to right, are Marcia Lucas, actress Verna Bloom, George Lucas, screenwriter Jay Cocks, and Nancy Allen. Standing from left to right are Paul Hirsch, Brian De Palma, and Paul Hirsch's wife, Jane.
(Thanks to Nancy Allen for filling in the gaps for us, and thanks also to Romain!)