Well, I’m assuming you know about 4K77 and 4K83? These are film scans of the originals, not edits of home video releases. Don’t let the “4K” fool you though, the 720p projects you’ve already mentioned have a lot more fine image detail. Nevertheless, they’re truly the original versions, and there are lots of versions to choose from – the initial scan is the same, but different color grades and levels of DNR are applied in various iterations. IMO 4K83 is definitely worth a look, but 4K77 is more of an acquired taste.

There are discussion threads for these project here, with instructions on how to get them.