The Stevens specialize in turning up seemingly impossible-to-find bottles, and in slipping their clients behind the velvet ropes for private winery visits.
The best distillers of their day, such as Pernod Fils and Edouard Pernod, were so concerned with knockoffs they used intricate wax seals and foils on their bottles, which, now 100 years old, are nearly impossible to fake, says David Nathan-Maister, a London rare-spirits dealer who specializes in absinthe.