quick google of collector car insurance reveals:
Grundy
Geico
Progressive
JC Taylor
Heacock Classic
American Modern Insurance Group
Esurance
Chubb
Barrett Jackson
StateFarm
Safeco
Farmers
I have no idea what you should expect from those listed above. I'd check with Hagerty first and then if you're ambitious give some other folks a buzz and get a quote. 15m could save you...???