There was a guy building great Willys bodies out of columbus. After he sold the company, he started working for hot rod shops. Try Amherst Classic Cars 440-985-2370.
They are in the same state as the company you are trying to find about about (Willys Hot rods in Mentor, Oh). I think his name is Keith?! I think the S-10 chassis idea is neat cause it allows a running start on a project. I think you are definitely doing the right thing by asking here. Maybe someone who has a body from Mentor will answer. Give it a few days.