I will go for the 3mm lexan, I'm sure it will bend a lot better than 600mm radius with care. The Broom has good fittings, channel up top and screwed into the timber around bottom using a chrome trim piece.
Nice to have a helper...I dont have any I'm afraid and do it all myself, kids getting older though and soon even the smallest will be too large to send down the bilges of the Storebro to clean up the mess Dad has made spilling oil so maybe they will be up to help
I can get 3mm cut for one screen at about £50 delivered or £100 for a full sheet large enough for 3.
Im a bit more encouraged knowing that others are using 3mm screens with no problems. I bought some plastic chrome effect trim for the top of the screen but idealy want something to lend a bit of stiffness.
Broom Broom thanks for the links and offer of your "excess stock" however I think it would be too wide for my purpose.
The minimum radius figures came from the perspex data sheet so are probably quite conservative a little light heat gun action will probably ease things.
Who is supplying cut screens for £50 its a bargain. My material came from Aquarius plastics in Guildford 1 sheet 3000x 1000 x 3mm smoke tint £68 +VAT best price anywhere at the time.
Mike's is about 6mm, but is a 'pro' job at expense. If you need his number PM me. Otherwise I found 3mm to be fine...is tough by the time it's rails are on and the only downside is that it's less scratch resistant than perspex. Bear in mind that our boats get used 5-6 times a year; as the screens we're replacing are often 30-40 years old, the new are unlikely to get the same abuse and will outlive most of us before they get crazed and scratched to that extent.
Have you tried Broom for the anodised ali rail they use for their screens?
My material I bought from Aquarius is tinted perspex. I have used the plastic shop for work materials but they didnt list sheets big enough for my screen.
so maybe they will be up to help 
