Stunner

Rocking All Over The World, most famously by Status Quo, was originally by John Fogerty from Creedence Clearwater Revival. I always thought it was common knowledge, but just in case, The Beatles weren't the first to perform Twist & Shout, but both The Top Notes and The Isley Brothers had had hits with the song before the Fab Four ever did.

I think the problem is that McCartney, Ram, The Plastic Ono Band and Imagine are essentially albums reflecting on The Beatles' split, so very few of those songs would've existed had The Beatles remained as a unit during the early 1970's. As someone with a lot more knowledge on John Lennon's solo career than any other Beatle, the only songs I can think of that may have been more-or-less the same from Lennon's first two solo albums would be Mother, Love, Imagine, Jealous Guy (which did start as a Beatles track, Child Of Nature during The White Album sessions), and possibly Gimme Some Truth. George's All Things Must Pass, however, is to the best of my knowledge essentially three albums worth of stuff that got rejected by Lennon and McCartney for recording, which explains how Harrison came up with a triple-album so soon after the split. Therefore you could definitely say the majority of those songs were written to be Beatle tracks, and so were more likely to have made a 1970/71 Beatles album. As one of the better Beatle solo albums, it pretty much proves to me how Lennon/McCartney's egos had ultimately got the better of them at that point anyway, as a lot of this "rejected material" is far superior to some of the stuff that Lennon and McCartney themselves had been churning out in that era. So for that reason, it was probably for the best that The Beatles came to a halt there and then.