Doug, I used 'pinchweld' as a term to decribe two panels that are spot welded together to form a flange such as the windshield retaining 'lip'.
You could do worse than shoot
Alan a PM.
He's gone through what you are and If memory serves me correctly he documented his work.
It sounds like a common problem with 2nd series trucks.
Give him a holler,I'm sure he'd be glad to help in any way he can..