Well done sorting your insurance ! I would have thought that the companies in the US that insure hotrods and such like would have been your best bet.
Over here in the UK there are several specialist insurers to choose from. Most offer generous discounts if ;
You built it yourself
You are in a club
It is a second vehicle
You want limited mileage eg 3000 miles
You don't have recent claims or license convictions
Agreed value in the event of a total write off is easily available too.
Fully comprehensive cover will typically cost around £200 - £500 a year for the average owner.