LOOK!! What is this for???

Doing some cleaning. Dont know where or when I got this hubcap but it looks interesting. Its hevier than hell compared to other hubcaps I have. This appears never to have been on a car and is pretty close to perfect. I dont know what im doing with it at this point but just want info on it. I have never seen one in this color. Every one I have seen was black painted and not this argent like color. Thanks for the help!!
Chas.