It's Reed Springs Chert, from pretty high up in the formation (where it gets confused with Keokuk). "Boone" is a generic term and many think that it should be done away with. The Boone watershed though covers many formations (Reed Springs, Keokuk, Moorefield, Warsaw, Barren Fork, etc).
Greenbrier don't occur west in the Ozarks. The Breckenridge highly resembles the eastern Greenbrier and are often mistaken for them though, as do a few other types.
Looking at the manufacture, I don't believe your piece is a Dalton. The deep basal indention, steep edge retouch, rounded serrations, I think it's probably a bit later than the Daltons. Calf Creek complex, and the earlier Coss as well, are well known for producing exotic pieces. Another possibility is middle Woodland. I have seen SEVERAL similar pieces come from middle Woodland sites in the Ozarks (all 4 states).
I'm not sure it's an intentional saw, but could be. The majority of saws I have seen have squared off or sharp serrations for a better cutting edge.