I believe Becket had a few roadshow screenings in 70mm back in 1964 and, according to the cue sheet, an Overture was created cutting and pasting these three cues - Triumph in France, Gwendolen's Chamber and The Banqueting Hall. The same edit was also used as an Entr'acte.
If anyone is interested, I've had an amateurish bash at trying to recreate the Overture courtesy of the excellent Intrada CD and Audacity. The cue sheet gives a duration of 3:50 and my attempt is 15 seconds longer, so there may have been a bit of cross-fading going on in the original.
Saw Becket during it’s Roadshow engagement in NYC and have always been disappointed that the blu rays did not include the Overture and Entr’acte. I remembered the use of Triumph in France as the major portion of the Overture but not the other cues . Thanks for putting this together.