That is a copy of the 'Kornburg Helm' housed at the Germanisches Nationalmuseum in Nuremburg, Germany.
Here's a photo of the original helm. The real helmet's ocular is painted that latten color, it's not brass or bronze, and the paint is not thought to be original. The mini-aventail hanging from it is also not thought to be original. It's dated to the mid 14th century. It's a cool looking helm!
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/98/1350_Topfhelm_des_Hans_Rieter_zu_Kornburg_anagoria.JPG/400px-1350_Topfhelm_des_Hans_Rieter_zu_Kornburg_anagoria.JPG)