I went with Grundy. Got a quote from Hagerty, and Grundy the same day. Couldn't see why Hagerty's quote was a $100 higher per year than Grundy, so went with Grundy.
I had Hagerty for several years and they kept raising my rates, so I got a quote from Grumpy about 5 years ago and the blew Hagerty out of the water and a better policy. Several on here really like American classic car. so it would be worth a looksee.
Heacock Classic. For true assurance that you will be completely covered. Get a Professional Appraiser to write it up and have the insurance company agree to the value.