Thanks guys! From what I can find, the prop is not a 12D40 from an AT-6. But is instead a Hamilton Standard 2B20. While it did have some military applications such as on the UC-78, traces of red paint on the tips (as well as yellow) lead me to believe this came from a 1940s Cessna or Waco.
So instead of painting the stand OD Green, I may just stain it dark brown. But, I am still thinking of stenciling, “Hamilton Standard Mod. 2B20” on the piece that supports the center cylinder.