Mark-
Yes, a long thread, but we're getting there, inch by inch. The collective knowledge of Stovebolters is pretty astounding and most useful!
Thanks for the clarification on the tilt-forward seat rather than a tilt-forward seat back. Perhaps this was an option in larger trucks, like the 3/4 ton model you came across. Also possible that some enterprising farm engineer added that feature without touching much else.
I was hoping for a modification or alternative that would allow me to get behind the seat. As I am adding seatbelts attached to the floor rather than the seat frame, an "entire" flip won't be possible.