Can anyone suggest an insurance company that will give me Class 1 business insurance for a VW campervan?

I am a self employed. I travel from place to place to work but I do not carry passengers.  I only carry my own personal equipment.  The campervan that I am thinking of buying has been professionally converted by a reputable company and it has been reclassified by the DVLA as a campervan. So it’s all legal. Specialist campervan / motor home insurance companies that I have spoken to so far are happy to inure me and said campervan for social & domestic use only, not for me to use to travel between my different work places. Van insurance companies will not insure it under a commercial van policy it’s no longer a “van”. Help!!