I'll save discussion of those two (and more) mic pre's on various Beatles records for the book. http://www.recordingthebeatles.com
It's not a simple answer in some cases. Until you know the different desks well, and then study the location of various recording/mix sessions, these simple answers don't cover it.
But I have the Revolution REDD.47 and love it a lot. I had an old V72 (modified to V72s specs for years before). The V72 version is warmer and smoother, more pillowy. The REDD.47 design is slightly more aggressive, and DEFINITELY has they type of edgy sizzle you hear on a lot of Beatles records. Still, a very high fidelity amplifier.
Just for fun, I made a track of guitar direct into the REDD.47 preamp overloaded. It was almost exactly that "Revolution" single fuzz sound. I've never found another pre that got as close.
(Don't forget that - in those days - a mic pre was also used as the line amp and makeup gain after processing. So it would not just be used once, but sometimes many times in the creation of one track's sound. Old desks did this a lot - Universal Audio, Spectra Sonics, etc.; one amp for the whole desk)