I too saw it with a full orchestra, but didn’t know that they found more footage. I wonder if it is available on Blu-ray disc. I would really like to see it again.
The British version does not have Coppola's score. It has a score by Carl Davis. Davis is a veteran composer of music for silent films, and he has done splendid scores for Keaton and Lloyd comedies and dramas like The Big Parade. His score is primarily arrangements of music by classical composers like Beethoven and Mozart. Davis's score was used when the film was restored and shown back in the early 80's. I actually prefer Coppola's score. It was kind of cartoonish, but the movie is a bit cartoonish at times. I know there are plans for a USA Blu-ray release. I don't know if it will include Coppola's score. It would require some re-recording to fit scenes that are now longer than they originally were, and would need music to cover the new scenes that have been added.
An added feature of the Blu-ray is that the three screen tryptich can be watched alone on three TVs and three Blu-ray players. One of the discs has the left side of the tryptich, one the middle and one the right. Presumably, it would recreate on one's home theater the sensation of seeing it on the big screen without having to letterbox the tryptich. I have no idea how one is supposed to synch three players as this is something I will never do. Still, it's a cool feature for some.
You can see some screenshots that show how they have cleaned up the film HERE.
I also compared the look of the earlier release with the new one. It is truly night and day. The Blu-ray looks exactly like the screenshots in the link I posted earlier. The old version was rather crude-looking, with many shots so faded they had almost no gray in the frames. Many scenes in the original release are cobbled together from several sources, so the quality varies from shot to shot in some scenes. In this new version, there is no jumping from source to source. I don't know how they did it. I know there was a lot of digital work done, but they must have found more 35 mm source material than was available back around 1980. The movie looks like 35 mm throughout.
The Copppola version was also sped up a bit back in 1980. It had to do with keeping the running time under 4 hours so that New Yorkers could still catch mass transit in order to get home from Radio City Music Hall. This version uses the correct frame speed, so some of the increase in running time has to do with that. Tonight I am going to try to find time for the Seige of Toulon sequence.