The only version of the rooftop concert making the rounds is simply the final two reels of the Let it Be film (with the exception of the extra stuff seen in Anthology and its promos). Having said that, I have audio of the complete concert, and most of it is much better than the audio on the film soundtrack. And of course some of the audio on the Let it Be album, in stereo, comes from the rooftop concert. And then there are the two Glynn Johns mixes of the album, which include even more rooftop audio in excellent stereo. It would be possible, I believe, to match almost all of the audio from the rooftop section of Let it Be with upgraded stereo audio from these sources to produce a better product.