Time and again you hear this kind of stuff. We can't find the tapes, we can't find the master etc... shouldn't be, like, proper and common procedure for a label to properly backup all the stuff that, after all, they own the rights for?
You would think, wouldn't you.
Never look into anime. The way Japanese studios store their stuff would make you have some kind of aneurysm...
Like... Seriously.
Toei have the original film prints and negatives used in the production of every episode, movie, and special from the original 1986-1997 run of the Dragon Ball franchise, but only have the original audio for the movies and GT, and only used the audio on the movies, but only for the home media releases in Japan. All foreign releases of the movies, and all releases of the TV shows use crappy audio from the optical film track, which are distorted and awful. Same situation applies to Fist Of The North Star, Saint Seiya, and Dr. Slump.
They also used the crappy '90s videotape master for all versions of the GT TV special aired, given to foreign distributors, released in Japan, etc., despite them still definitely having film of it... Which consequently means that while the video is awful, the Japanese audio is the original master, and since it was GT, it's even in stereo.
So... Just be glad our audio of Live In Tokyo isn't something like optical film audio in mono!!
Even DT haven't been perfect, though. Metropolis on 5 Years In A LIVEtime comes from a VHS tape, because there was no other master available. And there's the famous case from Chaos In Motion, where the multitrack audio they got for a few songs was from a different show, so all they had for the video version was the soundboard audio that was already on the footage, which they could EQ, but couldn't properly mix or anything.
And I do wonder if a lot of Chaos In Motion wasn't cropped for the DVD, but was only available from footage that was cropped to widescreen.