Here's some extracts of an interview with photographer & archivinst Joel Bernstein, conducted by the late John Bauldie for The Telegraph magazine, published in 1990.
Some of the interview touches on rare tapes, and Joel gives the following information:
In reference to the Salt Lake City 1976 show, of which there is no known recording:
John B: Salt Lake City's a very elusive tape
"I might even have a tape of Salt Lake City. I have a collection of some of those shows and some of the rehearsals"
Joel then comments on 'Blood On The Tracks':
"...Ellen Bernstein was the subject of a couple of songs on Blood On The Tracks...she also had this cassette from A&R mastering that had two versions of the acoustic Idiot Wind and two versions of the acoustic Up To Me. I don't know any other place that they appeared anywhere, but I will say that the ones that have come out are the superior versions of the two, but it's still interesting to hear them."
NOTES (by me, October 2010): Remember, this was prior to the release of 'The Bootleg Series' in 1991, so presumably one of the versions of 'Idiot Wind' may have been either the Bootleg Series take or the one fro the 'Blood On The Tracks' acetate. (don't believe what it says in 'The Recording Sessions', the organ isn't an overdub, but a completely different take, I had this conformed to me by one of the musicians at the sessions)
It's unclear whether Joel means that Ellen Bernstein had a tape that contained an ADDITIONAL TWO versions of 'Up To Me' that were different to the version releaed in 1985 on 'Biograph', but there's at least one other complete take from September 16th 1974 - as well as five takes from 19th September 1974, the last of which is the released version. None of the other takes have ever come into general circulation.
Joel goes on to say:
"...I have an alternate take of 'Groom's Still Waiting At The Altar'
NOTE: (By me, Oct 2010) : This isn't currently circulating, but I would assume it's one of the takes from 27th March 1981, Rundown Studios, which produced 11 takes...or Clover, 23rd April 1981.
The released take comes from Clover, sometime in May 1981.