Maybe it's the flint used--Mozarkite, I expect, or a 'rougher grade' of Burlington Chert, but the type knapping makes you think the piece was one of the Middle Archaic--or later Early Archaic lanceolate forms (Nebo Hill or Sedalia)--EXCEPT the lower lateral edges are heavily ground--that's Agate Basin workmanship, not a later 'knock-off'. Could the piece have been made by the Late Paleo Agate Basin peoples, then found and utilized by one of the later cultures--possibly...or possibly the tip repair, the conversion into a drill form, was done "in the field" (not at a home camp). When I start looking at a salvaged piece my first 'look' is at color--i.e. how are the flakes of the 'changed area' different from the body of the piece? In this Agate Basin's case the color (patina) is exactly the same--that tells me the piece was salvaged by the original culture. Even if it (the salvage) had been done 6500BP the patina would never perfectly match the 8500BP patina...and it does. Conclusion, the 3" by 1&3/16" drill form IS Agate Basin, guaranteed authentic, and from Callaway County, Missouri. Shipping is $8.00, checks or M.O>s are how I welcome payment. Sorry, I do not use paypal-type payment services--Roy A.