When I was building my deuce roadster I purchased a Brookville grill shell. When I tried to install the Dan Fink insert it was way off. Called Dan and he uses an original shell for his jig. I sent back the Brookville and "bit the bullet" purchased an original shell. The Dan Fink insert fit the original like Henry made it!!
I have never seen a reproduction shell but the cost, by the amount of work needed to accurately produce the original, is way over the market for a reasonably repairable original Ford. IMHO.