The trader trades in secret info that even Sherlock Holmes couldn't reveal in 1800's? In fact there is some suspicion that Holmes himself/or Doyle was The Ripper.

How did you know that? But you are quite right and Turnoi will support me on this. It is thought that French novelist Maurice Leblanc who at the time when Arthur Conan Doyle was writing the Sherlock Holmes stories and indeed was plagiarising Holmes, to start with including Sherlock Holmes in his own novels using the correct name and then when Doyle threatened litigation to brazenly change the name to Herlock Sholmes, actually believed Doyle to be Jack The Ripper. In fact if you read Leblanc's character Herlock Sholmes, he's nothing like the Holmes we know and love but more of a right psychopath; gunning people down in cold blood and the like.

As you pointed out how does Turnoi know The Ripper had blond hair? Did Arthur Conan Doyle or Sherlock Holmes have blond hair? Or wait a minute could Turnoi have been referring to Dr Watson? I am sure he had blond hair and he certainly knew how to use surgical knives. Crafty old Turnoi, he's been one step ahead of us and I have only just realised he referred to his fellow DR, Watson.