Then again, looking at this photo of the phase 2 set and comparing it with the one of Gene shot after Trek IV, the arched opening to the forced perspective set could’ve been much smaller in real life than the way it looked on screen

It’s interesting that in all the behind the scenes footage shot on the sets prior to TNG but after TVH, they never show that section of the engineering set. The reactor room was pulled away and used as the BOP lab in TVH, I’m pretty sure on another stage.

I never understood why the original engine room corridor bent to the right to create that entry alcove. Would have been better aesthetically to have it run straight in, perpendicular to the core. Always looked odd when viewed from inside the room because of the TMP k beams.

They left this poor guy alone in the desert for that same season.

Could be they set up the walls in free space to add the plant-ons or whatever. You see them in the background of the slide with the tank. This wall (closest to the bridge viewer wedge) looks like the e. room corridor leading into core. The taller flats being the east wall of the engine room.

I’ve see the proof sheets from where that first photo comes from. Sadly no color prints or higher quality images. I tried with an AI upscaler with mixed results.

They stole those panels from a Rebel Ship (or the The Making of Star Wars)

This is a photo from the back end of the force perspective tunnel in the engine room set. I believe this was taken around the time that they were tearing it down for TNG you can see how small the disks were at the far end where those conduits (and the ring in question) would be attached.

I want to think that the larger rings were made by combining two halves of the yellow warp core rings for Phase II and then modified and stacked together. Just a theory? Maybe that one for auction is one of the inner rings like this one (obv not 15”)

Awesome. Just visited the real spot. Though this section with the railing was built at Paramount to match.