I know this probably doesn't help you, but i have an agreed value on mine for 22k which i just bumped up from 20k (cause of rims and brakes and stuff) and i pay 750 a year through AAA. They allow me to drive it as a primarly car with unlimited milage since mine is a daily driver. I've had frineds with Novas and camaros who have AAA and one of which had the agreed value and decided to take an off ramp a little to fast and lost it. Car was almost totaled and they gave him no problem with his Agreed value of the car.
I need to check it out, seems to be much less than the policy I have with American Hobbyist or the Haggerty quote. My concern is modified or not. The standards seem to put my 72 in the modified category, although I don't think the changes in paint, interior, etc...define a modified vehicle.
I am carrying them on my '70 driver for the same reason. Decent rate, and more reasonable on usage. Never have heard about claims issues yet, though. They did just get done with a class action settlement about over charging or commissions or something, but I dind't bother.