For those interested archive.org has a much higher quality version of the recording [1] as well as a recording of the 1969 followup demo that explains in greater detail how the text editor works [2].
I really wish we could try NLS/Augment on an emulator but sadly it seems that it has been doomed by the god of copyright to forever rot in the archives of the Computer Museum.
The Hyperscope project died, apparently. I had to use the wayback machine to retrieve the source code but it builds on a couple of obsolete technologies (client side xslt and a javascript framework that's evolved well beyond the point of backwards compatibility).
I really wish we could try NLS/Augment on an emulator but sadly it seems that it has been doomed by the god of copyright to forever rot in the archives of the Computer Museum.
[1] https://archive.org/details/XD300-23_68HighlightsAResearchCn... [2] https://archive.org/details/XD301_69ASISconfPres_Reel1