For better or worse, Liquid Nails Fuze It.What did you use for adhesive/sealant on the ceiling wood?
Seemed to rate well on the internet and a few of the videos I watched (independent ones). I did screw it to the metal as well, so it's not just adhesive holding it together.
I did a trial of it with the ACP and it held well enough that I trust it for the paneling as well, although I will use a combination of some mechanical fasteners as well. With the surface texture of the wood and paint, I think there'll be no problem with it holding the plywood. It did an excellent job of bonding the alu as well.