Pete,
Sorry to hear you're thinking of selling - to me, your car is the "holy grail", my favorite among all favorites.
According to Hagerty's online valuation tool, a "Condition 1" car (best of the best) is just shy of $290K, "Condition 2" (excellent, winning local or regional shows) is about $225K, "Condition 3" (good, some issues) is about $118K, "Condition 4" (pitted chrome, chipped/scratched paint and/or glass, cracked dash, etc) is about $89K. Average for the car across all conditions is about $140.8K. Sounds like you have a Cond 2 car (give or take a bit).
There are other factors as well - is it a desirable color? Do all numbers match (probably given your knowledge of the car and its low mileage)? Stuff like that.
In addition to all that, how much you could get for it would depend on when/where/how you try to sell it and who the pool of potential buyers is on that, or any, given day. Finding just the right method/venue is the trick. (probably not news to you - sorry for stating the obvious....)
All that being said, you're probably looking at a pretty nice inheritance. The car should be an easy sell anywhere in the country.
Good luck.