Where does the vintage concept come from?
First to clarify that "vintage" is not a French word, but English (vɪntɪdʒ), referring to the vintage of a wine that with age usually increases its value, and that according to certain values related to the harvest, the brand, the fields, the variety, the vintage, exceptions (natural disasters of that year, bankruptcy of the winery, ...) etc., can make it increase much more. From there, is when the vintage concept moved to jewelry, watches and even cars.
It is not clear and it is a little static concept, with exceptions. Returning to automobile collecting, there are collectors who think that a car ceases to be old and becomes a classic when the price stops falling because it is considered old and starts to be revalued and valued. In cars it is more or less clear, but in watches there is no general agreement for the vintage clock concept.
We speak of designs or old or combinations of colors sixties and seventies. Very different shapes and extravagant straps. Dials not too large (without exceeding 40mm and normalizing male dials of 36mm, considered "feminine" according to current trends), innovative materials and different belts.
We must preserve the aesthetics and original pieces of the model and the time as faithful as possible. A watch kept as if it had left the factory in 1960 is appreciated among true collectors and investors. The same as with old cars.