I'd just be adding something I missed from Morrowind - one thing that stood out to me was Dunmer beauty practices. Men often had tattooed faces. This is a thing we still have, with war paint and everything, even in some of the oldstyles (Tribunal hand!). But on top of that there was http://i50.tinypic.com/28wiaad.png* - especially on the ladies; I remember almost every Dunmer woman in Morrowind had at least a row of pricked dots along each eyebrow - that hasn't been seen since Oblivion. Maybe it's fallen out of fashion in the time between Morrowind and Skyrim, but you'd think there'd be some still around anyway given how long elves live...
But this is the kind of thing I do: texture work.
I'm thinking new Complexion or Scars options. I don't play a Dunmer myself, so it's not really a priority for me to make a mod like this unless someone else misses these kinds of faces too - I might also go over some of the older or more traditionally-nimded NPCs and replace a few face textures just to make it all visible, but if nobody else is interested then making it isn't a priority.
If I did update the faces on some NPCs, who should it be?
*Screencaps from Westly's head replacer; chosen for clarity and retention of original Bethesda concepts