An HN search of ''Deep Space Nine'' and ''Topaz'' will show some great discussions here covering the dearth of such upscaling solutions, as well as some huge efforts before commonplace AI.
Links to the artciles found in those discussions are to some very enlightening efforts by Joel Hruska to find an upscaling solution related to what the person asked about. As somebody else mentioned, Topaz is out there and Hruska gave it a good shot, but it is not open source.
It's not exactly what you're after, as it's anime specific and you need to process the video yourself (eg disassemble to frames, run the upscaler, then assemble back to a movie file), but Real-ESRGAN is very good for cleaning up old, low resolution anime:
If you want to avoid manual processing, Anime4K runs in real time as a GLSL shader you can load into MPV (or Plex or something called IINA according to the readme) and still gives great results.
It depends on what do you mean by 'open-source', along with training materials and full setup? That will be hard to find. Upscaling was popular like 10 years back. That's why there is no much interest today. Training in old style isn't that hard. But artifacts are popping up in all videos I've seen.