Speak to Gott & Wynne. You should have no problems, and a better premium.http://www.gottandwynne.co.uk/
I agree, however we have only ever used G&W for the Mog.
You dont say how much you have been quoted. My wife' first ever own car insurance was for a 2007 1.8 4/4 was £280 with limited annual mileage (3000) & guaranteed value.
When we changed to the 2.9 Roadster one year later it only rose to £320 which was excellent. I'm not sure how much it increases if you increase the mileage limit?