Just checked both Ageco & John Lewis Insurance.
Both over £1000 more than current renewal quote.
Also checked with my local NFU branch.
It seems that 2 of the main parameters for the quoted cost, are Age and Postcode, neither of which I can do much about.
It also seems, that the fact that I have driven, probably over 500k miles in my lifetime, without an accident that was my fault, counts for nothing with current insurance companies.
However, I did get a small reduction for reducing my annual mileage to 7000.
Many thanks for all the replies so far.