First a few comments.
The premise of the show is that bootlegging is the bands' biggest problem. Never mind that their founder and co-lead guitarist was on the sidelines for health issues most likely resulting from the excesses of drug and alcohol consumption common among touring rockers of the 1970s. But OK, audience recordings of shows are your biggest problem.
Then they recruit a kid to make the recording using a large cassette deck with no external microphones, and he is gonna keep it in his jacket during the show, and record from the front row. There are so many laughable things about this premise:
1. The sound is often not the best in the front row
2. Security is often heavy near the front row
3. An internal mic on that kind of deck makes crappy recordings
4. Any mic inside a jacket, even a good one, would make a crappy recording
5. The kids are in no way coached to keep quiet near the microphone
Then, when we finally hear the tape at the end of the episode, the only sound we hear is of Rerun eating popcorn - not a trace of music. Really? A loud concert could not compete with the chewing of popcorn? Jeez, at least illustrate how crappy the recording would have been if you are trying to make a case here. And then add the popcorn.
But what about the performances? They are VERY interesting. First I should note that according to
this link the air date for part 1 was January 28, 1978, and the air date for part 2 was February 4, 1978. This makes all kinds of sense, because the arrangements of the tunes sounds very much like the Rainbow London, 8/31/77. Considering the lead time to produce the show, summer of 1977 is the exact time these performances should have been recorded.
The performances seem to be a mix of live and studio. And even the "live" portions were probably recorded before the video taping of the show, because most of what is shown appears to be lip-synched. But the arrangements presented are clearly from the 1977 band.
An interesting example: in the song Take Me In Your Arms, the backing seems to be somewhat live and in line with the 1977 arrangement, but the solo @ 7:33 is clearly the album version being "fret-synched" by Skunk. But on the same song, the vocal is by Michael McDonald, which is of course not the case on the studio version, and is the case on the Rainbow show. Notice also that this song "fades out" at the end, which it did not in concert.
Perhaps the most interesting part of the episode for me is the coda of I Cheat The Hangman, starting at 9:09am (again fading in, unlike a concert performance), but this is clearly not the same as the album version. It dissolves into the same sort of mayhem as the live version, ending @ 11:32. Amusingly, there is a part in the ending mayhem where the crowd is shown swaying and clapping to the beat, when in fact there is no longer a discernible beat to sway or clap to. It is a laughable attempt at illustrating the audience response to the music.
So to answer your question, I think the versions presented here are unique, although not strictly live, and possibly directly derivative of multiple other sources. Single elements in a given song may have been recorded live, like the gong crashes in I Cheat The Hangman. Or recorded specifically for this show, like the Skunk lead work in Takin It To The Streets at 14:03 - pre-recorded but unique nonetheless.
Finally, many of the songs have been edited - necessarily - to fit the format of the show.
Despite some of the weirdness I really enjoyed these recordings.
