The majority of the STAR TREK Feature Films do retain their original cinematic audio tracks on the 2-Disc DVD releases albiet in Dolby Digital 2.0 for the majority of TOS films and most assuredly 5.1 regarding TNG films. Would really like to have the PCM 2.0 and possibly PCM (possibly higher bitrate Dolby Digital) 5.1 tracks from these films from the Laserdiscs or the 35mm prints available for download and preservation. The recent 4K UHD disc and Blu-ray disc remastered releases of The Motion Picture, II: The Wrath of Khan, III: The Search for Spock, and IV: The Voyage Home omits the original cinematic English audio tracks for 7.1 instead.
STAR TREK VI: The Undiscovered Country would be the most trickiest since the original DVD release was still the Special Home Video Version which was sourced from the Laserdisc. The optical audio track from the 35mm film would have the original cinematic audio and original cinema cut of the film. That’d be an entirely different preservation project.
Not entirely certain as to what else to type except it’s been nice seeing the 35mm print preservations of The Search for Spock and The Voyage Home. Would be a nice project, perhaps also a massive undertaking, to preserve films The Final Frontier through Nemesis via the 35mm prints. Anything to escape the dreadful DNR and inferior sources of the 2009 BD releases of those.
I have absolutely no way to make my own preservations regarding these two formats. Don’t have any Laserdisc or film scanning equipment.