Pretty hard to say w/o seeing the photo. Is it online? Color or B&W?
Jerry playing any color SG past 1970 would be news to me. Sure it's not a red SG (maybe a brief revival of the '61-62)? Also, WHICH Fillmore- "East", "West" or "Auditorium"?
"There, in huge black letters, was 'The Grateful Dead'. It just... cancelled my mind out."-Garcia