Robert Mootz wrote:

But could someone enlighten me as to a) what specifically is the Gly 
Johns version ? b) are there any, ummmmm, current sources of such 
available commercially ?

***In the months after the "Get Back/Let It Be" sessions, the Beatles 
asked engineer Glyn Johns to put together an album. They and George 
Martin had already moved on to the "Abbey Road" sessions by that time 
and were not interested in the project. I believe there were two 
versions that Johns put together, both of which were rejected by the 
band.

I have the first version which has:
Rocker; Save The Last Dance for Me; Don't Let Me Down; Dig a Pony; I've 
Got a Feeling; For You Blue; Teddy Boy; Two of Us; Maggie Mae; Dig It; 
Let It Be; The Long and Winding Road; and Get Back.

The same CD, titled "As Nature Intended" also has the complete Apple 
rooftop concert on it.