Might be worth checking into. I don't have State Farm, but I had a '66 Chevelle that I had Classic Car Ins. through them. They had the best deal I could find.
I don't know if they (Farmers) do an "agreed value" like Hagerty and the likes. They just look at the NADA book and give you 80% of that if it is a total loss.
Any less they would just repair it. Make sure it's insured for the real value. Of course the higher that number the higher the premium.