I have both Grundy and Hagerty, depending on the car. Grundy is priced better for a completed car, but they wouldn't insure my project '36, for that Hagerty is my choice. Some have said that Grundy will insure a project (disassembled) car, but when I've asked if they disclosed that it was disassembled I've never gotten a reply. When I disclosed to Grundy they told me "absolutely not". Which brings up another commentary about relying on others for pricing info. Insurace is rated based on claims experience with similar vehicles, state and local rider requirements, AND geographic location. The identical car in Podunck, Iowa won't likely be priced the same in Los Angeles, best you request figures for your locale (as it sounds you have).
Also, if you go outside the specialty guys, make sure that the policy is for "Agreed Value", not "Stated Value". Many make the mistake of taking those terms as interchangable. A policy is a contract, and contract verbage has specific meaning. The primary difference between those two terms is in how settlement (if necessary) value is calculated. In "Agreed Value" if you pay for $10000 of value, they will settle for a total loss value of $10k. At "Stated Value", if total loss settlement is needed, the starting point is $10k, then depreciation is applied per the contract terms, and you receive something less than the stated amount.