Quick Q: how did you mask off the lime green icon on that vault? Or did you have to remove it? I never tried it, so I don't know how they're held in, presumably just glued on?
I wonder if hot glue is the best thing to use - is that what Oakley used on them? The thing about hot glue is that it's (obviously) instant, but not the strongest adhesive, and once a corner starts to go, if it's a flat piece, it ALL goes... I would use epoxy resin (provided you never, ever need to prize it out again - or if you plan to, use a smaller amount).