The original bolts for the seat back wood are a flattened head carriage bolt, as are many of the other bolts on the 82-A cab. The lower seat back wood is held in place by a slotted round head 1/4-20 screw. You will see both in the attached photo.
You will find some good info on the AA website by Neil Wilson regarding many things for the 82-A cab since this is the same cab used for both the pickup and the AA. Here's a post I found with a quick search for "visor."
http://forums.aa-fords.com/viewtopic...t=visor#p32735