WW2 aircraft seat mounting posts. I can't find them

[P-59A]

If you look at a number of my posts you will see I have a few WW2 aircraft seats. I didn't know how lucky I was to find seats complete with the post the seats mount to and in the case of my P-51 seat it also had the springs. It's hard enough to find period correct lap belts and shoulder harness's . A handful of times over the years I have come across these in very good condition, but they are few and far between. I have never found the seat posts or springs...ever. Now and again I come across the seats, but they almost never have anything attached. Has anyone found anyplace that has the seat posts and springs? I'm shopping around for the springs to see if anyone has a ready made item that looks like the originals. If I can't find them ready made I will be forced to have someone custom bend some. I took my complete seats to a metal fabrication shop that has laser cutters and found I can replicate the posts with all the mounting holes and seat positioning holes exactly like my originals in stainless steel. One offs are a little pricey and the numbers come down if it becomes a production run. My questions to all of you are does anyone have a hook up on the seat posts and springs? If not, is anyone interested if I do a small production run? The photo's show the two types of seat posts I am thinking of replicating and the springs.