Great pick-up! The Sullivan-DeWitt # is AL-1860-70. While there were many Lincoln campaign tokens or medalets, I believe that this scarce issue is the only full frontal view of Lincoln; all others, being a profile view.
Likely, the piece was once holed for suspension. It apprears to me that someone later cut through from the rim into the hole and sharpened the cut-out edge. I've seen a number of early coppers bearing similar sharpened-edge cut-outs. These coins were repurposed as cutting tools for thread and string; this, likely for use by seamstresses,etc.
Here's a large cent that was similarly repurposed ....

Here's my uncut Lincoln medalet ....


Likely, the piece was once holed for suspension. It apprears to me that someone later cut through from the rim into the hole and sharpened the cut-out edge. I've seen a number of early coppers bearing similar sharpened-edge cut-outs. These coins were repurposed as cutting tools for thread and string; this, likely for use by seamstresses,etc.
Here's a large cent that was similarly repurposed ....

Here's my uncut Lincoln medalet ....

























