Something definately aint right here, sorry but....

You've had the car 6 years without claim, you should therefore have 6 years No Claims Bonus, if it's protected then no problem, claim on the insurance.

Even if its NOT protected you lose 2 years from claiming on the policy, so what, you can still protect 4 years bonus!

IMO claim on your policy, get an Escos or at least 10k+ back and pay the extra few quid it'll be at next renewal