I Me Mine
This appears to be George's premier performance to the rest of The Beatles. The spoken intro would indicate that it's DDSI 08.02 from Nagra reel 80B from 8 January 1969 at Twickenham Studios. It might, in fact, contain other performances of the song from the Nagra reel which includes DDSI 08.02-08.04.
Why would an acetate of this performance exist? I would guess there are two or three possibilities. Perhaps at the time, George might have wanted an acetate for his own reference. Since the band did conduct extensive rehearsals of the song, perhaps acetates were cut for everyone to learn the song. A final possibility is the acetate was cut in January 1970 when George, Paul and Ringo entered EMI for the last time to record the studio version of the song and the acetate was cut as a reference.
The performances noted above can be heard on The Get Back Journals sourced from the Nagra reel (not the acetate).
FROM AUCTION DESCRIPTION:
It's a 7" single-sided acetate. Slight warp but doesn't effect the sound. Type written labels read "I Me Mine". different to released version same as the version in the Let It Be film. George introduces the song to the other Beatles "I Me Mine it's called. Shall I play it to you? I don't care if you don't want it on your show... it's a heavy waltz."