No Taleb,
Nobody knows ....
There are too many variables that "twist" the overall value of a car for sale.
A particular car has got roughly the value in its country of sale that is known there locally (let's say guided by the price guides of "Classicdata" in Germany or "Hagerty" in the US or similar).
In a given condition (good, very good, perfect or whatever) an original ZF 5-speed car is perhaps 5 - 8 Grand ($$) more valuable than a regular 4-speed.
But depends all on overall condition, restoration quality, etc.
Eventually/finally,
only the Market will tell you how much your car is worth.
The car is worth the price that the buyer is willing to pay and which the seller finally agrees upon.
Good luck with your sale
Achim
