Regarding the sound re-release, I found this info. It seems the above reel (Reel 5) is the only one to have surface, so far. The film was 10 reels in total.
The site link at the bottom of the post.
The Talkie Re-release Version (Talkie Re-release)Four years after the last footage had been shot for the silent versions of the Phantom of the Opera, Universal decided to make reissue it as a partial talkie. To do this, they reengaged Mary Philbin and Norman Kerry and some of the other original actors and some new actors to shoot new sound sequences that would be edited with the silent footage. Carlotta was now played by Mary Fabian, who could sing, and her mother was played by Fay Holderness for the talking scenes with the managers. Edward Martindel replaced John Sainpolis as Phillipe de Chagny except in a few long shots, and These sequences were directed in 1929 by Ernst Laemmle. Lon Chaney was under contract to MGM and Universal could not dub his voice. To get around this problem, they had another actor act as the Phantom's servant for those scenes where the Phantom talks to other people behind a wall or mirror. Once the Phantom as portrayed by Lon Chaney appears in person to Christine, intertitles resume and his servant disappears. The servant was played by Phillips Smalley. This was first released in Dallas and Detroit on January 3, 1930, but is mostly lost (see II-E, below, regarding its survival). It came in 10 reels.
What Survives:
Talkie Re-ReleaseThe 1929 Talkie Re-Release does not survive in its entirety. It had a Vitaphone soundtrack where the sound was stored on vinyl records or discs synchronized to the film projector. The 1929 Talkie Re-Release came on 10 reels and the ten accompanying sound disks survive. Of the film itself, only Reel 5 has been found and is currently stored in the Library of Congress, as are the sound disks. The reel is missing some footage, but Christine and Raoul have aged, especially the former. The Phantom's servant is visible in the newly-discovered Reel 5. Overall, there is about 1 minute and 15 seconds of new footage showing Christine and the Phantom's servant shot in 1929 and about 12 seconds of Raoul in footage shot in 1929 from this reel.
Here are the scenes with no corresponding video on the discs :
Scene 1 - Manager's Office: the Managers and the House Manager discuss why Box 12 has not been rented recently
Scene 2 - Outside and Inside Box 12: the Managers interrogate Madame Giry and investigate the occupant of Box 12
Scene 3 - Manager's Office: the Managers discuss the Phantom's demand to have Christine sign in Faust
Scene 4 - Christine's Dressing Room: Raoul asks Christine about her new-found fortune and her new admirer
Scene 5 - Opera Stage & Box: Christine sings in Faust and Phillipe warns Raoul about the Phantom
Scene 6 - Christine's Dressing Room: Raoul asks Christine again about her admirer and her Master's servant tells Christine that she should be prepared to go soon
Scene 7 - Manager's Office: Carlotta's Mother tells the Managers that her daughter will sign in Faust.
Scene 8 - Christine's Dressing Room: The Master's servant tells Christine to come through the mirror.
The film for this scene has been mostly recovered. Scene 9 - Roof of the Opera: Christine tells Raoul that she has seen the Phantom and they make plans
This link/page is chock full of info on the various POTO releases, discussion and details.
http://nerdlypleasures.blogspot.com/2013/12/versions-and-sources-of-phantom-of-opera.html