As per the recommendation by Photo Engineer in this thread, I've just got my hands on some Walther's Goo. I get the process of what I have to do: glue the thing back together. I'm just looking for any advice from those who may have done this in the past. Mistakes I can avoid? Something that seems really simple in hindsight?
The enlarger was in storage for the past five years, and the bellows has totally come off from each side, so I have to glue both the collar onto the bellows, and the whole thing back onto the negative stage. You can see the patient here: