OK, I called Grundy. They quoted me a price of $298/year. In the conversation, I asked the Grundy rep directly why their price was so much lower. She replied that they're restrictive on how the classic car is used. Driving to a car show, cars and coffee, etc. is legitimate, but using it to make a run to Home Depot or something of that sort isn't covered. They don't want you driving the car during rush hour, in traffic. They don't want it parked in a public parking lot, although parking at a car show or cars and coffee is OK. Guess that removes them from the discussion, as I use the Mustang to run errands and such, but always park where the likelihood of someone else getting close is pretty low
Bill