I'm not an expert in that era, but you should not attempt to clean it under any circumstances. You will do much more harm to its value than any
good. The Empress is fairly
rare, and if the coin is authentic, it would be a
good coin to have.
That being said, the coin does not look normal in those photos. You will need to post better photos and
weight and
diameter to get better advice. Try checking the
Fake Coin Reports section above to see if there is a match.