Mike,
Good luck on your search for a body builder. I don't really have any advice in that regard.
A few years ago, there was a guy in my area who decided that antique cars would be a good investment. He started attending the big auctions where he would have the opportunity to pay full retail +++ for most of what he bought. He had the added problem of not knowing anything about old cars but his check book apparently worked flawlessly.
One of the cars he bought was a Model A coupe, which he later sold to a friend of mine (also not a particularly saavy car guy). I went with my buddy to get the car and as I walked up to it for the first time, I instictively felt under a fender to see if it was steel. It was NOT. Mr investor had bought and sold the car without knowing this, and my friend had paid steel fendered car price for a glass fendered car. The car had no shocks and some other problems as well.
I'll get back to the point of this narrative. Another car Mr. investor bought was a Model T with a wooden enclosed panel type body. The car was nicely restored and the body was well built, EXCEPT that it was an Oak duplicate? of the original Poplar and Pine body. It was so heavy that the car sagged from the extra weight and thus had an ugly stance that ruined the whole package. The car came to our local show once, along with "before" photos of the car with it's original body... I wanted to cry. The original body only needed a few repairs, not replacement. Mr investor was, of course, unaware that there was anything unusual about the stance of his car or that it looked ridiculous.
Keep this in mind when you find someone to build your body. Your car is not sprung to carry a heavy body. Original bodies were built of cheaper and lighter weight wood than Oak.
Sorry for such a long story for short warning. Good luck with your project.
Mike
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Many miles of happy motoring