In reply to Removed UserGRUMPY MONKEY:
When I insured my new (as in old van but newly purchased) campervan 2 years ago, they accepted my no claims from my car insurance. My car was insured with Toyota but I got the camper insured through Adrian Flux , I think Zenith Marque is the company they used.
Don't know if this is any use to you, the two vehicles are still insured separately but on full no claims bonus. Good luck.