Insurance Help

I'm now at the stage where my Clipper is garaged for most of the year & only out in the summer. Is there any companies out there who insure for 6 month & then just a fire & theft for the other 6 month while it's garaged. A mate says he got fire & theft on a really old transit camper van he came across & decided to do up. I'm lucky if I do a thousand miles when it is out. Any age restrictions don't really matter as I'm an old codger (41)
Any help?

Not so much part-year but limited mileage policies get cheaper the less miles you do, you can declare 750 miles, or 1500, or whatever.