The Final Show That Wasn't

During the filming/recording of Let It Be - as heard on the Let It Be
Naked extra disc - there was talk of putting on a concert either in the
Sahara or on an ocean liner. Other venues may have been discussed -
and in the end all we got was the rooftop concert. However, as I
haven't got any source material myself and little time to web-search to see
what's out there, can I ask the group to answer and/or speculate?

How far did plans for this concert go?

Was there any discussion of a potential set list? (Let It Be material,
some of their old hits, the old rock'n'roll classics that they jammed
on in the film?)

Were any additional musicians expected to be involved? (Billy Preston
perhaps?)

Was it planned to record this as part of the Let It Be film/record, or
as a separate venture?

plan, probably because of the back seat he and his songs would have
taken - as was evident during the rooftop concert, but also I think I
heard somewhere of a "fear of flying" (or at leaast a serious dislike).

Mike...

I just started reading "Fear of Flying" by Erica Jong. It's a bit
whiney so far.

All serious input welcome.