Rear hood pin mounting on a Duster

Hey guys, I'm installing a pin on hood on my 72 Duster and was wondering if anyone has pictures or ideas on how to mount the rear pins. I was thinking about making a bracket to attatch to the firewall but I'm not sure how to attatch it seeing as I cant get to the backside for bolts. What are you guys doing with a lift off hood with 4 corner pins?

Butch