[Dominik]

When I inquired for my Maserati replica the designer who created the 3D model "spoke" to the manufacturer directly. They were discussing cord lengths and other dimensions. Pilkington (N. Gardiner) actually had Maserati A6 glass, but not from the Berlinetta Coupé.

3D scans are easy and cheap nowadays. Perhaps even people who print in 3D have handheld scanners.

Otherwise, old school, I sent a shaped aluminium sheet to a local manufacturer (in SA).
They create a template on pins, almost like a needle bed, and drop the soft glass onto it.
Youtube should have videos.

A plexi might change shape in transit (open up).