This pen knife? was found with some other items, including a tombac button. If I understand correctly, tombac buttons were a second half of 1700s thing. Am wondering if the knife might be that old.
Looks kind of like the style that used to be called a jack knife.If so,they,ve been around a long time.Mid 1700s,I don,t know that,s a long time for steel to be in the ground and survive.