Coin i.d.?

Yesterday I posted a photo of my dad's 1817/3 half dollar. I mentioned he had another older coin in his small collection. Here tiz! He was never able to i.d. it and I'm hoping someone here, by just seeing the faint silhouette of the figure, can take a stab at it. To me the outline of the figure looks like George Washington's outline. The few letters that are legible at the 2 o'clock position appears to be C O. Possibly for the word COLONY??? The reverse side is completely void of any identifying image. Where my dad found this. We live in western Pa. In the country. We live on a private dirt/stone lane. While walking the lane one day in the 1970's he looks down and finds this coin. The basic property, according to my grandpap, was at one time American Indian territory and the lane may have been an original trail. My dad's guess then was the coin got to where he found it by way of Indian trade. But who knows. The odds of my dad finding the coin is crazy. Probably erosion made it surface. It appears to be copper,, possibly bronze. About the size of a current 50 cent piece. So, any good guesses? I just want to know what the coin is. The value is worthless due to condition. Thanks.