As a Star Trek fan and as someone who took the time to rip the BR disc into my streaming collection with the original soundtrack and FX, here are my comments on the originality and quality.
First the series was indeed messed with, but this first happened back in the 60’s. There are records of what opening titles each episode initially had and several of them have been changed. But that was not a new change and it was done to the original negatives.
Second, a must have for anyone looking into this is the soundtrack box set. It has all the original recordings as well as the new titles recordings. From that it is clear that all of the BR original soundtracks have the original music. None of them have been updates with the new recordings.
I’ve been watching Star Trek TOS faithfully since 1984. I am very well acquainted with what we had back then vs. what we have now. The colors prior to the recent scans are horrible. The command uniforms wash out to gold from their original avocado yellow-green. That happened in some FX shots anyway, but most of the shots should show a distinct green tint. That is how you know you are looking at a good scan. This was confirmed by James Cawley who was friends with Bill Theiss and secured a sample of the original uniform material which verified that it had a distinct green tint. Star Trek New Voyages/Phase II and Star Trek Continues fan productions used the correct colors for their uniforms.
The remastered versions corrected many small inconsistencies in the episodes and those are NOT reflected in the original cuts. Some are very subtle and would be easy to miss, but they definitely are not there in the original versions included in the blu-ray set.
Prior to home video release, we were subjected to edited versions on TV. 4 minutes was cut from each episode. the first time most people saw these (who had not collected the VHS or LD releases) was when the SciFi Channel aired the extended versions with commentary in 90 minutes slots. They aired the episodes twice, once with Shatner introducing and once with Nimoy. While the episode cut is the same, those versions had incorrect colors.
I am satisfied that the episodes as delivered on Blu-Ray, when played in their original form, are indeed original. In order to create the remastered version, they went back to the original negatives and scanned them. This represents the best version of the episodes. If you want to undo how clean they made them, add some film grain, but there was no release prior that is as good. I’ve seen them all. My understanding is that was the first time they went back to the negatives so in terms of picture and sound, they should be the most authentic to how they were aired originally.
Now, The Cage. That is a different story entirely. Gene owned the negative and a B&W print. Both complete. I do not know what transpired exactly. I’m sure NBC viewed a color print, but no one has mentioned it. But when it came time to do The Menagerie, Gene brought in the negative for them to use. He expected them to copy it. Instead they cut it up. I’m not clear on the sound, but I think the sound was a separate element. The original sound appears to be lost. Gene’s B&W print made the convention circut and received some damage over the years. One section of dialog, which was captured by an in room audio recording by a fan, was lost. When they went to do the first VHS release, he wanted The Cage included so they made the hybrid one. They took the audio and video from The Menagerie and created the first mixed cut. This was the first most fans had seen this. Then a miraculous thing happened. The cut footage was found. So the next video release (The mixed version came out as episode 1, the restored version came out as episode 99 - I had both VHS tapes and was very pissed off that people thought 99 was colorized). And you can tell where the footage changes because it was not the same scan. They literally scanned the missing parts and edited them back in. But that missing dialog was not included. When they released the DVD version, both parts were scanned the same way so the footage was more consistent. When the BR came out, they had rescanned it again and you can’t tell the difference. But in each case the edit where there is missing footage is noticeable because the video is different in each edit. But really only in that one spot.
Now I can’t speak for the quality of the audio tracks on the LD vs. the DVD vs. the Blu-ray. I have not looked at those. But my experience with Star Wars indicates that those old LD AC3 tracks are as good as any modern soundtrack. The analog ones likely have more noise, and given the copy history of these episodes, probably has a lot more noise which is not original to the episodes. Until the remastered, they were using a film print as the source for all the home video releases. So the Remastered (and hence the original version on the Blu-ray) went back to the negatives and is made from the best sources. It should be the most faithful to the original you can get and I am satisfied with that. No, some of the episodes are not totally original as to how their originally aired, but they are faithful to their first rerun (Which is when some of the opening titles were changed).
But that soundtrack box set for TOS is a must for anyone investigating the sounds of TOS. It is full of information and glorious music (not just the often repeated tracks form previous TOS soundtrack releases).
Ok so from what it seems like you’re saying, the mono tracks on the BDs of TOS are not downmixes