Nope, nothing inside the toroid besides a heap of white gunk. I've tried digging away at some of that glue (it's not going to be subject to a lot of movement or vibration, so I'm not too concerned about that - I can always silicone or hotsnot it back in place if needed) and all I could find was the labels for the two wires that come up and disappear into the transformer. They're FL2, so just a filter. The big toroid is L1, so an inductor. No sign of any empty holes in that area where a thermal switch could be wired in, either.
That said, right next to the fan connector is an LM358 op-amp, a couple of diodes, a TO-92 "Q6" which is probably a transistor, and that green thermistor. Those together could well form a speed-control circuit for the fan, but that doesn't explain why we have no speed control on it (unless it would speed up if I took a heat gun to it!). Maybe that little circuit was just wired out of the system for some reason.
I'll try to get the 24V supply open when I stop for lunch. Hopefully that'll be more obvious!
Awesome Bit faster than mine, then! Mine was pretty much exactly 4 weeks. The UPS delivery took several more days, though - ground transport from the south-ish of Spain up to the south of England.