They wouldn't have strictly needed 8 or more communicators, even more phasers, two Gorn suits ... but we know they had them nevertheless.
Is it really necessary to keep debating this? I'm not taking one side or the other, merely pointing out that both possibilities exist and we
can't know which one is correct without evidence.
So the question is, is there evidence? Does a close examination of the turbolift scenes in TOS reveal any physical differences, e.g. the floor-display panel being a different distance from the wall seams or the handles having subtly different dimensions in different scenes of the same episode? If such differences can be observed, it would confirm that there was more than one turbolift. If they can't, it would suggest that there was only one, or else that the builders did a really good job building two identical ones.
Now, you could be right; it does seem like just one could have been technically sufficient, if unwieldy. But instinct/gut/common sense tells me that having a second lift over in the corridor complex would have been better overall than moving one back and forth every week for three years.
That's certainly true,
if they had the budget for it, but TOS was a show that had to economize like crazy. It had to make a deal with AMT to build the shuttlecraft and the Klingon battlecruiser in exchange for the model kit rights, and it had to pass off Wah Chang's props as study models so they didn't have to pay full price for them. Given that, it's plausible -- not necessary, but plausible -- that they might have needed to economize by not having duplicate lifts.
And I still think you're grossly overstating the difficulty of moving the turbolift walls around when stagehands carry much heavier things around as a routine part of their job. I mean, it's not an actual working elevator, it's just a few sheets of wood. I doubt there was even an actual floor or ceiling. As I've mentioned, they had to remove walls when they shot a scene from the side, and any scene looking toward the rear of the lift would've required moving the lift set away from the doors so they could fit the camera in. So it is a given that at least one lift set
was routinely moved, and was designed to be easily moved.
And if it had been just one, then I can't explain the two different floor colors: surely they would have brought the blue carpet swatch with them when they moved it.
Probably the reason there are two different floor colors was because it was just a few wall panels that they put down on the existing flooring. There are plenty of older shows where, if you look closely at an "elevator" set, you can see that its floor is just a continuation of the stage floor, with no seam like a real elevator would have. It's just a few walls stuck together.
The lift is more of a room than a prop
Which is exactly my point. A prop is generally a single intact object (though there are props, like the modern TARDIS exterior, that are designed to be broken down and reassembled for easy transport). But a room within a TV/movie set is just a few flimsy walls that are usually designed to be removable to make room for cameras and lights.
Can we take this scene as one data point in favor of the production wanting to avoid the time and expense of moving turbolifts around?
Again: Moving things around is a constant, routine part of TV production. When moving from a bridge shoot to a corridor shoot, they'd have to move the big heavy 1960s cameras, the big heavy 1960s stage lights, the microphones and sound equipment, all the electrical cables for the above, the ladders to help them set up the overhead lights, the chairs for the cast and crew to sit in, etc., even aside from whatever corridor walls they'd have to add or remove to accommodate the camera setups they needed. Moving the 6-9 lightweight wall panels of a turbolift set would be a trivial addition to all that.
—it was replaced with another which was subsequently painted the same as the first.
