Detrimental64,
Look at the coverages for each feature of the various policies/companies that you are considering. Where I live, State Farm could not even come close to cost, amount of coverage, and driving flexibility (I could only drive to car events - shows and parades) that I now get from
Hagerty Insurance. Grundy's coverage looks to be similar to Hagerty's. It also looks like Grundy's (posted by Horvath) will insure muscle cars (and thus might cover vehicles that have been modified/rodded). Hagerty and Grundy both have an on-line quote form.
Note: you cannot make a cost judgement based on comparison of prices quoted here. The level of coverages might not match and there are different price structures for different cities/states.
Both Grundy and Hagerty allow leisure, non-commercial driving of your vehicle and I think that neither one had a mileage limit. I pay extra for a enhaced towing option (can't be too careful with these old vehicles). My two policies with full coverage (no deductibles and full-replacement of agreed upon values) is $288 per year for two vehicles with $35,000 total full-replacement value (I am in NY state, so this rate might be lower in other locations).
Tim