most insurance policies carry windscreen cover and will direct you to their nominated one. You will not beat any of the nationals for a professional job

I disagree.

The nominated national glass repairer for my insurance company I wouldn't let them touch my vehicle after my previous experience of dealing with them.

There are plenty of smaller independent automotive glass replacement companies that work on reputation by doing decent work & not by relying on tv advertising or insurance company contracts to flood them with endless work.

The screen isn't chipped or cracked but leaks capaciously. I contacted the insurance and they don't cover leaking screens.

Ask a mate to crack it!

Not too close to you but try Old School Windscreens , Longcross, Sy. They were able to sort my Audi S2 many years ago ( rare and problematic ). They were very helpful and did a very good install.

A few years ago my Outlander was in for service and the screen cracked on the test drive. The dealer surprisingly didn't suggest I claim on my insurance, they got their regular, trusted local firm to do it. I was very pleased with the result. I've had a couple of poor jobs from the big Nationals.

Yesterday the car was in for an MoT. The tester commented that I must have had a news screen, and it wasn't a genuine Mitsubishi one. I asked how he knew - the chassis number couldn't be seen through the viewing window at the bottom of the screen.