Insurance is my business. I sell over 30 lines just for auto.
All my old cars are insured through Hagerty. In my experience there is no other choice due to their "user friendly" relationship with their insureds.
Also, since they are the largest insurer of collector cars, they also have the best (by far) network of parts locating, and shops that are expert in repairing the old cars.
In any event, you are looking for/need an "Agreed Value" policy, which sets an absolute value agreed to by you and the insurer (no appraisal necessary), NOT a "Stated Value" policy. I can't tell you how many people have their cars dramatically under insured without realizing it, after all you can "state" the value of your car at a Million dollars, but should a total loss occur, It could be a numbers matching Hemi survivor and you will get a settlement offer of a rusted out slant 6! --- Even though you have been paying a rate that is based on a Million bucks. This is because "collector value" has no bearing on replacement value of a "69 Dodge Coronet", as trim packages and options are valued in the $100's of dollars or less.
I recommend you call, or go in to a Hagerty agency. Of all the insurers I have ever dealt with, I have never had any problem (myself, or clients). with them.
My experience anyway. --- By the way, beautiful car!