[Neil Wilson]

I did some more research and found that the original top hinge rod is about 1/64th less than 3/8" diameter. And yes, this hinge was a seemed tube.

Vendors sell 3/8" diameter stainless steel solid rods. Snyder's sell "not solid" rods (but they don't look like the original seemed tube). It looks like 3/8" diameter rod is available industry wide.

Basically, getting the original .36+" diameter is not feasible today.

The Ford engineering drawing would likely provide the diameter they use.