Since more of the film has been discovered since the early
80s, that makes things a bit problematic.
There have been three scores written for it: Davis’, Coppola's and Arthur Honegger’s (for the first screenings in the 20s.)
The difficulty would be new scenes. I still have not watched all of the Blu-ray (even though I have had it for a couple of years), so I am not sure how much is new material. There are several scenes involving the daughter of Tristan Fleury (the guy who is a cook during the Brienne scenes and who chews up some documents to save Bonaparte during the Reign of terror). She basically worships Bonaparte and has a little shrine to him. Her scenes are not all that great, IMO, but I imagine they would require a new theme as the "love theme" that Coppola composed would be reserved for Josephine. They will either have to come up with a new theme from another composer, or use an existing classical piece (Coppola used a few classical pieces in his original score just as Davis does).
Maybe I can make my way through the whole film this weekend. I keep putting it off. Watching silent movies can be tiring, because you cannot take your eyes of the picture and follow it as you can with a sound film.