i don't expect miracles , just throwing it out there .the back is pretty worn and damaged from the elements but any help to narrow it down would be helpful
I won't say with 100% certainty, but you can compare the features better in person with the one on the coinfacts site that I think it is. A Miller 33.1-Z.13
I beliieve some key features are worn off or just do not show on the photo to say "without a doubt"