The method to produce Sherry and the respective Brandies, called Solera, uses several layers of barrels (frequently four layers). From the lowest layer they take the annual amount they want to sell and refill from the respective layer above. The layer on top is refilled with the newest production. So every Sherry and Brandy produced in this way contains at least (four?) year old wine or spirits, but also much older components of the first year of production, which means that you may expect a drop of first production year in each bottle. ;)
This is why you will not find a year of grape harvest on the bottle labels.
However, except those mentioned in Wikipedia I do not know any other winery or distillery working in that way. I know some that blend (mix) different products at the end of production, but that is not the same.