Joan was good with the Dead in '03, and the PLAF show on 10/30/05 at the Hard Rock in Vegas had Joan, which sounded good as well.
Don't know about the UC...definitely sounds like Sless, but the other player? Larry has that Nashville meets Chicago Telecaster sound...I don't think it's him, personally. Ck out the NJPAC shows to see what I mean. Sless sounds like Jerry, even more than Herring did. Could even be Warren.