Thanks for the picture of the wheels and shafts. I am not sure how those fit into the top and bottom of the seat adjustersand if 1947 was the same as 1950 3100. I am making some 5/16" dowels 1 1/4" long to put in to hold the top and bottom together on each side. If you have a picture of how those pins and wheeels fit in I would sure like to see it.

As for the springs, I found the ones that were in my truck, so I am set on that. I have been looking at Denny Grahams pictures and they have helped a lot. Here is a link that shows one of those springs in place:

https://pbase.com/dennygraham/image/158845500

If you look at the next few pics he has you will see the dimensions of the spring so that you could get one or two at your local hardware store. There is an error I think in one of his pics as it has the same length dimension for stretched out vs. compressed in succeeding pictures. It is obviously longer stretched.

Good Luck!!

Jerry