Sorry to be picky,
but there is no such a thing as a NEW 1973 Ford Mustang.
In my world, a " new" car is one that was manufactured on a particular date, then was shipped to a dealer hitting the showroom, and then was sold on to a customer as a new car. That process has a limited life span of one calendar year maximum from manufacture date. Anything out of that time, and the car looses it's "new" status. Within that calendar year, the car can have several miles on the clock and still be called a new car.
A similar concept applies to a customer who has just bought a new car from the dealer. He takes it home and calls his car a new car. But for how long can he keep on doing that? Again, when that car is more than one calendar year from manufacturer date old, it's not a new car anymore. That's a given, as a new model will be released the next calendar year anyway. If he decides to resell that car on within the first calendar year, it will be sold on and becomes a second hand car. That's understood.
So a "new"car has a life span of one year max from manufacture in the true sense of the word. Dealers, who sit on stock that is slow to sell, and run out of time when that calendar year expires, cannot call that car a new car anymore. Of course, many do and try to cheat.
Anyway, that's a nice car.
Greg.