My day job is being an insurance agent with Va Farm Bureau. I have many clients who have classic or restored cars insured through me. What we have them do is get an appraisal from a body shop and give us a few pictures of the car. We then put an endorsement on their policy to cover the car for the "stated amount" value of the appraisal. There is minimal cost to do this and it establishes the value of the car prior to any loss and makes dealing w/ a claim much more favorable for them.