Help Identify Strange Mask

(I'm not sure that a bell that cracks on the first ringing would be a great selling point for the foundry.) I guess I didn't realize that the original bell was melted down and recast here after it cracked that first time and it cracked again years later.

 

I'll take a stab
Brass.
Front is polished, back is not that is why you have two different colored metals. Also the back appears to have a little corrosion (whitish areas)

Appears it was meant to hang and the hook broke, so someone used wire to hang.

Interesting that the one eye is open as if it was meant to be looked through.

I vote decorative.