I am surprised at this, my experience in the past has always been that the insurer will ask you to fill in an aviation questionnaire and then decide whether to increase the premium. I have never had a problem obtaining insurance, even when I informed my life insurance company that I flew, skydived and bobsleighed!- they still insured me but simply increased the premium. There are some specialist insurance brokers who advertise in the back of some of the flying mags – might be worth having a word with them.