Ranging a bit farther afield, I wonder similarly about Sun's NeWS, which
I never saw in the flesh.

Branden,

You may find this fellow’s archaeological dig on NeWS and PostScript interesting: https://twitter.com/rsnous/status/788053163857379328

He also attempted to make a NeWS clone: http://dev.rsnous.com/dewdrop/executive/ (source available).

Josh