Thanks for the tips guys. I got it done, and it was quite a bit less daunting that I had anticipated. I used sandpaper to remove as much of the old adhesive as I could, then I glued the bellows to the collar first (it was the top bellows... the one on the condenser lens), let that set overnight, then glued it onto the negative stage the following night.

Now I just have to get the rest of everything set up, and I'll be printing again! I'm super-excited!