Bonding Fiberglass scoop to a steel hood

I would look into the bonding adhesive used to attach Corvette panels. It's a lot like bondo. Corvettes have metal reinforcements behind the fiberglass and the bonding adhesive is used to join panel to panel and also panel to metal. Just make sure you're going to bare metal and you rough it up good. I would use 36 grit on a DA sander.