For spy enthusiasts and collectors, World War II's infamous Enigma machine is one of the most sought-after historical artefacts — with only about 300 left worldwide. But for Sydneysider Mike Pritchard, he happens to have three in his storage. These cipher devices were developed and used mainly by Nazi Germany to encrypt and decrypt secret messages. "It's actually not my favourite machine, but it's the one that everybody knows. When I take these sorts of machines out to show people, they're fascinated," Mr Pritchard said. " It's the most magical thing to see. It's intoxicating. " There are believed to...