the bottom pivot and the truss rod is from a murray springer very common like on poppawheelies RRBBO bike they are the cheapest used springers you can find mine was 9.99 on ebay they were common on murray, sears, higgins bikes of the late 50s early 60s I considered using the original main forq from the murray but its not wide enuff at the top to bolt a plate to hold the spring but something could be welded to it then the spring bolted to it which I am going to do with the left over pieces then I can play with the design and see which I like bestcman said:Hooch that is beautiful. And so simple. Please post detailed pics of all points. From what I see, building this from scratch might not be to hard. The bottom pivot looks to be the most crucial.