Many thanks, everyone!
After my first visit here, I was shown a set of photos from another building on the campus, and my jaw just about fell through the floor. I slacked off last weekend, but yesterday I made the trek back down. The atmosphere couldn't have been more different; while two weeks ago was brisk, sunny and featured great fall colors as a backdrop, yesterday was cold, gloomy, drizzly and bleak. The perfect setting, in other words, for a place like this.
Interestingly, this building provided a much better vantage point to see the rest of this half of the campus, and I couldn't see any signs of the demolition I've heard so much about. I also once again saw no sign of security, but I did notice several regular cars driving around at points, possibly full of curiosity seekers. This stands in stark contrast to a lot of what I've heard about this place.
One last note: I also gave the tunnels here a try, and they were without a doubt the worst I've encountered as an explorer so far. They were all of four and a half or five feet tall, and about three feet wide, half of which was taken up by a large pipe shedding its asbestos cladding. I made it maybe 200 feet in, stooped over and barely able to see despite my flashlight, before I started hyperventilating into my mask and had to turn around and get back to fresh air. To those of you who've successfully navigated them, my hat is off to you.