Point well taken and stated Brino!
Wed, I picked up a rear wheel hub/bearing and tire/rim from a VW Jetta. Next is to weld the axle shaft into the hub. The other end of the axle is where the crankshaft plate will mount. That plate will have a center hole (for the axle) and an offset hole (3") that will make the connecting rod go up and down, pushing the leaf spring up and down, operating the hammer. Got a 3 leaf spring (97 dodge truck) and removed the center spring. Reversed the small spring and sucked them down tight with all thread rod. While still held with the all thread, I stuck the assembled (now flat) spring in my big vise, added a large c-clamp to the top so I could take the all thread out and install the grade 8 bolt and washers that will hold that spring together in operation. The reason for turning the small leaf around was specifically to straighten the assembly. Still need to make the connecting rod throws which will be sched 80 black steel pipe with grade 8 3/4" bolts through them. All rotating points will either be tapped for grease zerks or simply drilled for oil holes if clearance doesn't allow for a zerk, or the attachment of a grease gun.
Should have another photo or two tomorrow.