I have to disagree with those advocating State Farm. I was insured with State Farm for years. Years ago, I bought a Fiat Spider Turbo (ok...stop laughing now - it was a great car). It was a legitimate, company manufactured car. But, it needed a lot of work, and a lot of modifications were made. Where I live (Minnesota), the state requires a vehicle examiner review any major modifications made to a car before it can be licensed/insured. All the work was professionally done (and quite well, too), and the inspector had no problems. He signed all my paperwork, and a license was issued. Did State Farm accept that? No, they did not. My agent almost herniated himself laughing at my request for insurance. The "modifications" made it uninsurable. We had a lengthy discussion, and I was told that while you might be able to slide a car past underwriting (maybe), the second you file a claim, they will do "post-claim underwriting" (meaning reexamine the policy and find a way to claim it never should have been issued) and refuse to pay it. Sure, they'll insure it sitting in your garage and not being driven. But, if you drive it and something happens, they will refuse to pay and then cancel your other policies. State Farm simply doesn't want to insure these cars.
The "collectible" insurers (Haggerty, etc.) will only issue policies that cover the car to and from events or shows. Very few companies will cover a car like this for everyday use. I looked far and wide, but I did find one (Liberty Mutual) that would issue a policy. I read the policy, and there don't appear to be any weak spots. But, then, I've never filed a claim either.
Food for thought.