So, it could be "Yakov-zhelezen" or "Ivan-zhelezen", (where the adjective follows the noun it modifies, so it would be more like "Jack of Iron" in Russian as opposed to Iron Jack) or some other variation along that theme.
BTW, Joseph Stalin derived his name "stalin" from the Russian word for steel, so "Stalin" means "of steel" or "like steel" in Russian. (He was a native Georgian by birth, his real name was Joseph Vissarionovich Dzhugashvili). Many thought he was a real "zhopa" too.
I love languages. I would love to read Dostoyevsky in Russian. I called the Russian embassy in Washington and asked for the correct pronunciation of Rachmaninov and Karinina; they were very helpful.