This point was found along Onondaga Lake - Central NY. Doesn't it really look A LOT like your pic #3 ! Could flint/chert from Central New York look that much like your Coshocton flint? Maybe some Ohio flint was carried to central NY?! I would call this a Brewerton Corner Notched Point.
If it's yours is coshocton Ontario then it was carried there or traded. I also would like to think it could have traveled there in finished form with the guy that made it during migrations? Probably a stretch but who knows for sure. It's a nice piece regardless. The area of ohio I'm from there's not much good local flint mostly white cherts. So we find flint from quarries quite far away. I'm atleast 100 miles from flint ridge, or coshocton quarries and we find hornstone from Indiana. So you might be surprised how far stone can travel.
This point was found along Onondaga Lake - Central NY. Doesn't it really look A LOT like your pic #3 ! Could flint/chert from Central New York look that much like your Coshocton flint? Maybe some Ohio flint was carried to central NY?! I would call this a Brewerton Corner Notched Point.
Found this a little north of cayuga lake which isn't too far from you. though its different material, looks to be similar type. Fairly certain mine was a big knife.