Hi Tim,
I've had both mine come off:
1'st march 2016, when boat 17 months old,
2nd March 2017.
A good contact adhesive properly applied seems to work well.
With that kind of adhesive it has to be smeared completely over both faces to be joined, left for the stated period to cure, before pressing together.
The impression I got with both is that this hadn't been followed to the letter at build or fit-out; old glue didn't cover the whole joint.
Have used contact adhesive for catamaran centre board gaskets, and found it holds fine, the gaskets wearing out before the adhesive fails. Nail varnish remover Acetone used in moderation good for removal.
Jonathan 1141