What could this piece be?

I was supervising the restoration of an old stone wall around a cemetery that dates from the 1700s to the Civil War era. The rocks were all dry stacked, and the wall had been neglected for many years. Some of the wall had toppled over, and much had been pushed out of alignment by trees and privet that were allowed to grow against the wall. While the crew was carefully removing the rocks, this item rolled out. I believe it is a 10% lead alloy of some sort and it has an eagle on it. It is also quite heavy. Any idea what this is? Seems to be overkill for a cane tip or umbrella. Strange piece indeed.

 

finial, for a gate..grave marker, flagpole , fence post.....or the like.... I'd surmise !