There's no many info about this point, sorry :-/ ... I've found out:
George Harrison 1970 - 1971George Harrison - Guitars, Vocals
Dave Mason, Jesse Ed Davis, Eric Clapton, Don Preston, Bob Dylan, Peter Frampton - Guitars (Sessions)
Klaus Voormann, Carl Radle - Bass (Sessions)
Gary Wright, Bobby Whitlock, Stephen Stills, Leon Russell, Billy Preston, Gary Brooker - Keyboards (Sessions)
Peter Drake - Pedal Steel Guitar (Sessions)
BADFINGER - Guitars, Percussions (Sessions)
Ringo Starr, Jim Gordon, Alan White, Jim Keltner - Drums (Sessions)
Bobby Keys, Jim Price - Horns (Sessions)
Phil Collins - Percussions (Sessions)
Phil Spector - Vocals (Sessions)
from here:
http://members.tripod.com/rant58/id285.htm (notice that it says 1970-
1971)
and this ...
THE FOLLOWING MUSICIANS CONTRIBUTED TO THIS ALBUM: Drums and Percussion:
Ringo Starr, Jim Gordon, Alan White Bass Guitar: Klaus Voormann, Carl Radle
Keyboard: Gary Wright, Bobby Whitlock, Billy Preston, Gary Brooker
Pedal Steel Guitar: Pete Drake
Guitar: George Harrison, Eric Clapton, Dave Mason
Tenor Saxophone: Bobby Keys
Trumpet: Jim Price
Rythm Guitars & Percussion:
Badfinger Mal Evans: Tea; Sympathy; and Tambourine
and introducing the George O'Hara-Smith Singers
Orchestral arrangements by John Barham.
Recording Engineers: Ken Scott and Philip McDonald
Package design & Photography Tom Wilkes and Barry Feinstein for Camouflage Productions
Produced by George Harrison and Phil Spector for Apple Records.
from here:
http://web.mit.edu/scholvin/www/harrison/c301.htm (but Phil Collins is not mentioned :
)
I'm still researching ...