Hello Jack,
Here is the process that I was thinking of.
1-create the shape in fiberglass. For this car I would start with a block of foam and create the shape. This gets covered with a few layers of fiberglass and finished off like a painted body part.
You have to make sure when making the mold that you allow for the thickness of the laminated glass for the finished piece.
2-Brace the piece (actually done before doing the body work. If using a thick block of foam to form the shape bracing probably wouldn't be required. Ship this to the windshield manufacturer
3-The windshield manufacturer will build a metal jig from the mold for forming the glass.
The jig with the flat laminated glass is set in a furnace until the glass takes the form shape.
The final glass
These pictures are not my work. They were posted by a guy that has done a large number of custom windshields. I did check prices years ago with a US manufacturer. I don't remember what the price was but I know that I thought it was reasonable.
I actually worked in the glass industry a life time ago and I saw glass being shaped.
Any way, this is the process I am aware of.