If you are talking about an older short-door car, then Melvyn Rutter is probably your best bet. He does complete widescreen reburshment kits, including rubbers and windows (which I think are polycarbonate/Lexan)
Tim H. 1986 4/4 VVTi Sport, 2002 LR Defender, 2022 Mini Cooper SE
Can someone post a photo of the new rubbers. If anyone is interested I have 2 bits of Perspex cut to be one panel of a sidescreen for a short door car.
JohnV6 2022 CX Plus Four 2025 MG ZS EV aka Trigger
They don't fit all cars John....it very much depends on the clearance between the front of your side-screens and the screen pillar. They are not expensive and if they do fit, they hold the sidescreens firmly. I'll pop out into the garage later and take a photo.
Jays Former Morgan owner. Gone but hopefully not forgotten!