Chances are you’ve never heard of a quiet, unassuming 50-year-old Vietnamese businessman named Viet Nguyen Dinah Tuan. But if you’re a whisky collector, you probably know about Macallan’s Fine & Rare Collection—periodic, extremely limited offerings of some of the Speyside distillery’s rarest and oldest single malts. And if you’re really a staunch fan of collectable whiskies, you may also have heard about the Springbank 1919 single malt, which was released in 1970, with only 24 bottles produced.