I had a look at the channel and wondered why there was no true archival version provided by either:
1. The channel org itself via "Internet Archive" and/or torrents.
2. The community. It is trivial to create archival copies of youtube channels and most rare true archival footage on youtube will be mirrored elsewhere, even if "illegally".
(1) does not exist and (2) is non existent either, no one considers these encodes valuable enough to preserve, which does seem odd considering it is unique data.
Load up the videos, and you see a giant watermark, thus destroying any archival usage.
No one will fight for this channnel, no one will bother mirroring it, because every encode is ruined and flawed.
If the channel/org has the originals, consider talking to Internet Archive