Without pressing the point, "original pronounciation" is in the eye of beholder. Sydney born Mark Rudan introduces himself as Mark Rudan, and is referred to as such, on FOX Sports, while the old Croatians call him Rudan.
The highest peak in Australia, Mt Kosciuszko, was named so by the Polish explorer, Count Strzelecki, in honour of the national hero of his motherland. The name is commonly pronounced by the locals anglicised, that is " /kɒziːˈʌskoʊ/, and not the way this name is pronounced in its original Polish, that is "/kɒˈʃʊʃkoʊ/ .".
The moral of the story is that the origin of the word is one thing, but it may ultimately also belong to people speaking a different language.
As the famous line from "The Deer Hunter" went, with Robert de Niro's character being asked by his army superiors: "... Michael Vronsky... what kind of a name is that?" and de Niro's response: "It's an American name".