The analysis of the Culver City backlot shoots is impressive. I'm surprised at how often the various shots were consistent with one another about where the actors were in the backlot, only occasionally doing the kind of location jumps like having Kirk and Spock run into one alley in one shot and be in a different one in the next. If you compare "Arena" to the real geography of Vasquez Rocks, you can tell they're jumping all over the place from shot to shot, their movements not corresponding to reality at all (because there were only so many positions and angles you could shoot, particularly with that big "Cestus III" fortress standing nearby at the time).
Any more shots of the Desilu soundstages at Culver City? I just saw the first-season Mission: Impossible episode "Action!" which takes place in a film studio, and the studio exteriors they showed didn't seem to match the photo of Desilu's main studio (the one next to Paramount) at the front of Inside Star Trek. However, looking at the photo of the Culver City soundstage complex on the site, I think it may have been shot there. Which is odd, given that M:I was filmed on the main lot, right next door to the Trek stages. Maybe the main studio was too busy for them to film exterior scenes of a fake studio there. (How far was the Culver City "40 Acres" backlot from the Desilu/Paramount lot?)