Photos of the spring (#2) that I'm looking for. In the photos you sent (post#5, first photo), notice the HOLE in the seat lever, ...that is where one end of the spring attaches.
I 'borrowed' the spring (shown in this photo) from my '68 50th. BOTH trucks had this spring.
Photo of the broken spring (hard to see, but broken on right side of spring coil, I just placed the two pieces next to each other for photo)