You need these lovely people....
http://www.4counties.co.uk/motorcycl...insurance.aspx
http://www.4counties.co.uk/race-insurance.aspx
..they insure both race bikes (for ACU License holders) and track bikes along with transporters etc. etc. etc. in the U.K. and for overseas events.
Not actually as bad as you might think, especially if you do a lot of track days, test days or race.
Bex, even if you don't plan on racing, it might be worth looking into getting an ACU License (you can do it all in a day at Brands the same as Steeevooo and I did for around £150 all in) as then you could go along to open pit test days which work out way better value than track days generally.
To give you an idea, before it all went to poop Mallory was only £60 a day open pit which means you can go out on track as you please throughout the day.