Thanks to all of you on this board for your ideas and help!
I'm buildin' door panels for the coupe and all of the info for me to do them came from the Hotrodders board. The amount of info on here is just great.
Toyota makes a neat door panel fastener. Round hole in both door panel and door metal/ car door. Fastener is about the size of a dime, unlocked center pin is pulled out toward you. Locked, the center pin is pushed in and becomes flush with the rest of the fastener. Really a neat set-up and one I think I'll use to secure the door panels in my 63' Bonneville.