I don't exactly have a rat rod, but I have a homemade tractor my grandfather built mostly out of automotive parts from the 50s/60s. I've been semi-restoring it and have found helpful tips and interesting discussion on this forum. I have a question or two I wouldn't mind asking so I figured it was about time I came out of the shadows and joined.
I've been told the front axle "looks International" but I don't know for sure.
And yes, the sheet metal does look International, almost identical to the Farmall A except with a mesh grille. I've read power unit shrouds of that era were often styled after tractors.
Mind if I chime in???
Grille, hood and radiator are IH Farmall Model A with the horizontal grille pieces cut out and perforated installed.
As far as the rest, your guess is as good as mine