Now this one would be interesting if it were a lamination error on the obverse. I'm pretty sure it's not zinc rot, or post mint damage. What do you guys think ?
I agree it's definitely no zinc rot. Looks concave to me. Possibly struck through debris? Lets see what the pros think. The grey background helped. I hope you don't mind I cropped and scaled up your photo. Its a little blurry...I can't fix that.