You're welcome, Tom. Finding that site was like being a kid at Christmas. I am in love with the thing, LOL! There is lots of info about the shows as well, including the source of the tape. There are some poor recordings there, but the majority are soundboard derived. Ck out Wembley/London in '72...polar opposites and an exact example of what I mean...one day is a horrendous cassette recording, and the other is straight off of the board a la Alembic's Europe '72 LP! It has the same sound, balance and feel as the album, and the song selection and performances are excellent. It's probably no secret that I share my favorite Dead incarnation with Susan: Pig Pen and Alembic's recordings! The '72 tour was probably the best ever, and there are many examples of same up on this site, including the U.S. before/after Europe dates.
BTW: get 'em while there hot. The site has a writen disclaimer about the Dead's official recording policy which allows non-commercial use of any of the unofficial recordings. As soon as they make an official release a la Dick's Picks or Rockin' the Rhein ('72 Rheinhalle/ Dusseldorf, Deutschland), they take it away (unless it was a non-soundboard recording). I just glossed over the thing, but you get the idea.