Here is a photo of a copper bannerstone that I got off of arrowheadology. I need to track down the source and also need to see of there are other items like this.
---http://www.arrowheadology.com/forums/arrowheads-indian-artifacts/14150-show-me-your-copper.html
Patrick,
I don't know if you found what you were looking for on this copper banner stone but I found some documentation on it.
In Byron Knoblick's 1939 book
Bannerstones of the North American Indian he has two photos of the bannerstone, some back ground and some measurements. Page 323, 334-336 is the reference.
The banner is 5 inches wide and the blades are roughly 5 inches tall. The thickest part is about 5/8" thick with a 3/8 hole drilled. The report says 1/4" but I measured the full scale photo and the hole was 3/8. The rest of the banner is thin. It was discovered in Wisconsin and is thought to be the only example of its kind.
The image you posted looks just like the one pictured here. That right side has the same indentation or damage.