You mean the one Stills is playing? Yep, looks like the right headstock, but I couldn't get a clear view of the front...even more fascinating is I'm sure that's David Crosby sitting in with 'em...(1:39 and 2:49) According to Wiki that would have closely coincided with his departure from the Byrds... :?:
Or maybe it precipitated it? A little googling shows the Byrds were there too: http://www.youtube.com/watch?v=E3nVLI5XTXE