Is this 2015 missing the outer layer,? I don't know anything about clad or missing clad but the 12015 is really dull as you can see in the other one. is this environmental? I'll
It looks environmental. A missing clad will be light in weight and copper in color. And if it was burnished it would still show plenty of luster. Yours doesn't. Probably left in a solution that etched the surfaces.