Just to finally follow up, I used double-sided trim tape and it has worked well. I used a 3M, 1/2" x 5 ft. roll for $6 from an auto supply place, which will do 2 enlargers.
I couldn't find the black tape but the gray/brown worked; it doesn't matter as there's really no thickness to the tape when you join the metal plate and the bellows and there are no light leaks. Just scraped the old glue off the metal plate and pressed it to the bellows.
I think this is a good alternate to messy glue as I've read the E-6000 has a terrible solvent odor that does not go away.