A Beginning was always a G. Martin composition even when it was used on the Yellow Sub soundtrack. And it always will be since that is how it was published. If it was actually used as the intro to DPMB, then who knows whether the composer credit would have been Martin/Starkey or just Starkey..? Something was always a G. Harrison composition, regardless of the arrangement. For example, what is the composer credit on "A Day in the Life" (Orchestra Overdub) from Sgt Pepper? Or "Eleanor Rigby (strings only)" (Take 14) from Anthology 2? Are they credited to G. Martin or Lennon/McCartney?