Always an interesting subject.
Most folks are not aware that the different "sellers" of antique auto insurance are not the ones providing the insurance coverage. You may be buying insurance from Grundy or Condon/Skelly, but the coverage is "underwritten" by such insurance companies as Zurich, Foremost, Metlife Auto, Philadelphia Indemnity ... and so on.
And the actual underwriting company may differ by state.
Not that it matters. You will hear very few stories, if any, about somebody not being treated fairly by any of the antique auto insurers. There has been a lot posted, price seems to be the major difference.
Even more unusual, companies like State Farm and Nationwide, rather than write you on one of their policies, may place your coverage with Grundy who in turn places it with ... XYZ company.
One caution. Insure your car for what it's worth. You can insure it for less and hope that any damage/claim wll not be for the total value of the car ... you can get that bent fender fixed and the company will pay 100%. BUT, if you do have a total loss, agreed amount or whatever, they will not pay more than the policy total.
... and if they do pay the total, they get the car.
You have the right to BID for the salvage value.
True story. Model A roadster. Hurricane Katrina. Total loss, $10,000.
The car had belonged to the insured's father and had been completely restored. It was worth quite a bit more than $10,000. In order to make a claim for the 10K AND get his father's car back from the insurance company, the insurer owner would have had to beat the then high bid of $12,000 ... the salvage value.
Incidently, he took the 10 grand and somebody else paid more for the salvage than the insurance company paid for the loss.
Read 'em and weep.