Shake, rattle and spray:
Jeez, what did I use to glue that paper to the fins… hairspray? (I think I probably know what I used, and I don’t use it any more.) I decided to try fixing the problem with contact cement, partly because it happened to be out. I peeled the paper back gently, snuck the cement in on both surfaces with the broad end of a flat toothpick, let it dry, and pressed it together. Looks okay so far. I’m not painting it, though, until it’s had a chance to volatilize most of the stinky stuff.