Come to think of it...Dennis' last full show with the band was in Sept. 1983 at the New York State Fair, about 60 miles north of Binghamton, and that IS an outdoor venue. I wonder if this could be pictures from Dennis' last show?
These look very similar to shots I've seen from their July 4th Atlantic City Boardwalk show. Oh, and apparently Dennis' last stand at the L.A. County Fair in Pomona was closer to a full show than we've been led to believe...while he may indeed have shown up a ways into the show (for "Warmth Of The Sun", based on evidence from the audio recording), he apparently stuck around to the end...I bought some pics off e-bay, and Dennis is seen playing drums with Bobby, with Mike K., by himself, and doing "the dance" during "Barbara Ann". (before anyone asks, I can't post those here or anywhere else...it was a condition of the sale)