In reply to Justin T:
Try NFU mutual, for the same cover they were hundreds and hundreds of pounds cheaper than adrian flux. I really believe that AF trade on being the "standard" answer when folk as about self convert van insurance.
Ours was a basic conversion though (sleeping platforms, insulation, a couple of hobs and a grill) but adrian flux and most other insurers wanted a fortune to insure us.
When I asked NFU about the changes, their comment back was "hahaha, that's nothing compared to what we get asked to insure by farmers!!".
The service we've had from them has been fantastic as well when we had a claim a couple of years ago.
Cheers,
Stuart