Mickey & Billy sittin` in ??

I`m looking for some information on where and when either Mickey or Billy K have sat in w/ other bands. I`m intersted in concert appearances as opposed to playing on other people`s studio recordings ( the GD discography has that information available if needed ). I`m aware of a few times

DP 28

In you listing of songs not on DP28, you forgot: 2/26/73 Deal 2/28/73 Promised Land They are not listed on the Dead's website: http://dead.net/merchandising/music/DECD208/