You would have seen any imperfections in TMP when you saw it in the theater............
hi-def or Blu-ray is NOT a better picture than a movie has to begin with.
In fact, Blu-ray is still far less resolution than 35mm film.
If you had looked at that matte in 1979 you would have seen the same thing and maybe even seen more of it's 'unreality'.
The difference is of course that you would have been looking at it for the first or second time and would have been less attention to background detail.
Same with TOS. Yes you can see some imperefections, but we've (most of us) seen these episodes umpteen times and you start to occasionly wander form the story and look at minute details.
you show somebody who is open-minded about older sci-fi, but has never seen TOS----they will likely enjoy the episodes greatly and not pay that much attention to a loose thread on a shirt. The 20th time they sure might.