Large cent countermark?

Hello, have this large cent worn so hard to see something, but there is 15stars so it could be onnly 1817. Large Cent Matron Head Type 1. 15 star so if someone know something more please tell me something aobut this counter mark hit on reverse, and some for value this coin

Looks like only 13 stars to me.

where are you getting “15 stars” from?

Maybe this will help:

Hello,

I follow “countermark” and “counterstamp” as search terms on eBay and I'm quite sure I saw this c/m recently.

All it is is Mᶜ so it's most unlikely anyone will ever identify who did this and why. 

It's usually the case that even complete names are difficult to attribute — names like “W. Jones”, “J. Simpson”, etc. 

As for the host, I have myself identified a few countermarked dateless large cents, or at least greatly reduced the chronological span to a few years. The first step is to compare the hair locks at the bottom and back. I use this excellent site.