When I was first working on my Falcon, I bought a lot of clips, bolts, and weatherstripping from Restoration Specialties. Their web site isn't very high tech. You'll have to download a pdf catalog and browse through it.

http://www.restorationspecialties.com/index.html

Did you check with West Coast Differentials about the bolts? I'd be surprised if they didn't carry them or know where to get them.