You can bet the master tapes of groups like The Beatles and Pink Floyd are let out once in a blue moon. In fact, when talking to several people at CES this year, it's getting increasingly difficult for those doing remasters to get the original 3 track master tape. And as Allen Sides told me, and who's to disagree with him, the two tracks pale in comparison to the original three track tapes.
I thought Sgt. Pepper's was originally recorded on 4-track?