Karen, yes they did play Gimme Some Lovin', A classic Winwood tune from his Spencer Davis Days, and it was indeed wonderful. The debate in my mind is whether you can claim "ownership" of a cover.  Another Winwood tune, Dear Mr. Fantasy, also made it's way into the rotation around that time, and I loved it, But I never really thought of it as a Dead Tune.  Same with the myriad of Dylan songs they began to play in the eighties.  (Did you know that after Garcia/Hunter Bob Dylan is the single largest contributor to the Dead songbook?.)  On the other hand, if the version is definitive, why not?  I think more people today would associate Not Fade Away with the Dead than with Buddy Holly.

As to Gumbo Moon:  JT, in the Archive, states the last time played was in '05 or '06, but provides no specific date.  toofarnorth says 6/12/10 at Webster Hall, but Eric disagrees (I was also at that show and I don't remember it, but memory is a funny thing).  KC uploaded a video with an upload date of 11/8/08, but the video does not contain the actual date of the show, though I assume that it could well be contemporaneous.  Ah well...the truth is out there...somewhere.