I'd say a 1 of 1 car that has survived 95 years is beyond "novel". I would put it down as the rarest Model A ever produced.
Not in the best shape in my book just means unrestored - which is where the value is in a car like this.
It's too bad the owner has decided to hide it from the world and not let others enjoy it.
It was 1/2 million on FleaBay.
https://www.fordgarage.com/pages/1931stainlesstudor.htm
While it may or may-not be 'novel', the reality is this vehicle at even $500k pricepoint is worthless unless your ego is involved.
FWIW, years ago when it was listed on eBay, I spoke at length with the Nephew (-as I recall) from Indy that was representing the car for his Aunt because I had a customer from Canada who was genuinely interested in purchasing the vehicle if a deal could be made. In the late 90s when this was being discussed, we determined that the car could likely be professionally duplicated for in the $100k - 125k range since all that was unique to this vehicle was the 'sheetmetal'. After much discussion, the consensus was if that vehicle was cloned, likely it would receive much of accolades thus severely diminishing the perceived value of the original Allegany Tudor. In reality, the sole 'novelty' of this vehicle is to see a Tudor Sedan with a Stainless Steel Body.
This is why I feel the vehicle has never truly seen a sincere buyer. There have been discussions over the years that this was actually a project by Allegany Metals -and not Ford. Kinda like a prototype Firetruck that was built by a Fire Apparatus company on a Model-A chassis, -or an airplane or a piece of equipment that used Model-A mechanical components. The Allegany car really was not a Ford-built vehicle unlike the Edsel Ford commissioned LeBaron bodied Dual Cowl Phaeton, or the 1946 Ford Model-A that Gregorie built for Henry Ford II (who also commissioned it), -or the surviving Budd-bodied 3-window Coupe that the Ford engineers commissioned. So why is this Allegany Tudor any more valuable than any other era modified or custom built body that was put on a Model-A chassis??
And realistically, if the Allegany vehicle were in a museum, how many people would actually make a special trip to a museum just to see the original Allegany Tudor? Of those, -how many would take the time to make a second visit of the vehicle? For me personally, it has a place in history because of its uniqueness, but it's true value is likely much less than what the above-mentioned Ford built vehicles are if they were in the same condition.