Insuring a home built van.

Hi All. I am new to this forum and am looking for advise from the many experts here.
We are almost finished building our 5th wheeler from scratch and it is fast approaching time to register and insure it. Our usual insurer, AAMI, doesn't insure home built vans. Can anybody recommend a reputable insurer who does?

Any advice or experiences would be greatly appreciated.

Thanks, looking forward to hearing from you.