Pilkington glass offer an extensive array of classic windscreens and will also undertake bespoke manufacture or one-offs.
Start with looking at their classic and kit car section. No dimensions I am afraid but will give you a good understanding of what might work for your project.
You can then create a short list and start searching for dimensions. Contacting owners clubs and visiting classic car shows, auctions and garages.
https://www.pilkington.com/en-gb/uk/...kes-and-models