I found an interesting site http://rarebeatles.com/ghpsatmp.htm
which publishes a letter by Phil Spector to George Harrison with remarks about some early mixes of the All Things Must Pass album.
It dates from August 19, 1970, which is possible because the recording started some months before and the release was in November.
Most of the comments refer to the buried vocals, which indeed on some songs have remained but on some have improved. Other things are about Bobby Keyes' sax parts so he played a large role in it.
Something I do not understand is that he refers to the vocals of 'Eric and Bobby', this would be Clapton and Keyes, but I find that hard to believe, knowing EC's vocal talents of that period and never heared Bobby can also sing (which is also hard during live performance, to play sax and sing at the same time). I always thought that all backing vocals come from Hari as being the George O'Hara singers. Anone knows more about this.
Read this and shair your thoughts. I have listened to the songs and have the following comments
All Things Must Pass
By leaving the horns out in the intro we would be close to the Anthology version, which I would have prefered now I read this, but George desided otherwise.
Beware of Darkness
The electric guitar up-front was left and I consider this still to be a good thing.
Let it down
I agree with the remarks about pronunciation of words, because it is still hard to hear what the words are in this song.
The screeming sax came in.
The bridge is there and includes heavy Bobby Keyes appearance.
Anyway, in case this document is original, I would love to read any follow-up and the parts that were left out.
Look forward to comments.