I was doing some research on rye whiskey and found a reprint of a Pennsylvania news article from 1902. It reported on a wine and liquor merchant in Green Lane, Pennsylvania (not sure if that locality still exists) with regard to rye whiskey. The merchant was a widow who took over her husband's business and considerably expanded it. There are many interesting details. Her ryes were between 5 and 20 years old. She bought in carlots to offer lower prices and only sold the best quality. She had just got in some 20 year old rye. It had been distilled in Pennsylvania in 1881, aged 13 years, then was sent in cask to Bremen, Germany because of the beneficial effect of sea transport on the flavour. The story said that most "high grade whiskey" was shipped overseas for that reason. The story said the whiskey was brought back 7 years later to be sold as 20 year old rye. It noted when the owner opened the casks, being 44 and a half gallon containers, between 14 and 20 gallons were left, reflecting the evaporation that occurs with long aging. The lady thought the rye so good she ordered numerous more casks to sell.
There was a tradition of sending some wines and liquors across oceans to get the accelerated aging and other effects of different temperature zones and the salt seas. Those briny Islay and Campbelltown whiskies got the Atlantic maritime effect by staying right at home, of course. Maybe this shipment practice was done in part at least to emulate that effect. The Norwegian Linie Aquavit is still shipped across the world over the equator ("linie") to mellow in this special way. I think the effect on the rye in question might have been to give it a slight salt note and maybe a sherry-like fruitiness. There was a practice for many years of aging brandy and rum in London, England (and Edinburgh) to get the benefit of long aging in damp, sea-influenced cellars (the "old landed" cognacs, ports, etc.). It appears Bremen's warehouses did a line in the super-maturation of fine spirits as well.
It is hard to think anything could improve Mr. Van Winkle's wonderful rye whiskies, but I wonder if sending them to a damp European port for 7 years might add that "extra special something"?