Never heard of green rock from KY. Also never heard of people finding it that far east. But i would not be surprised.
You can find balls of flint in Bowling Green, they will have a light colored chalky crust and will be blue, gray in side.
Your best bet is to drive the roads between Bowling Green and FT Knox and look in creeks and any were you see fresh earth from construction is worth a look.
I'm sure your find good flint, you just have to put the time in.