Have you seen Brian "The Obscured Guy"'s tab? His are usually pretty accurate. I used to have a Mayonaise acoustic tab that was accurate, it had a weird alternate tuning that was in line with the one on Mashed Potatoes, Still Becoming Apart, etc: www.spfc.org/data/music/gtab/mayonaise-1.tab
It might be the same tuning as 'Guitar 2' on this tab. Not sure. Looks about right.