I use Haggerty because they seem to be run by enthusiasts. I didn't really shop around though(not at all really). I've had to use them once for a flat bed tow home, and it was fine. (not for the Durant, for one of my POS British cars, although Mike,it looks like you will also be experiencing this). They also put out a real nice magazine!
I switched from Grundy to Hagerty for the same reason, they are car folks and if you remember two Hagerty people rode with us on one of the days during our Traverse City meet in Michigan.
Rick
Where Are You From? Fremont, CA
Do You own a car built by Durant? 1931 Model 619 and 1929 model 60 Roadster