They are the low/mid string definitely - Chorus and Record have 4 arms with the 5th concealed behind the crank arm (like Suginos), all others use the same body with improving levels of finish. But you can take a cheaper Mirage one and polish it up to make something as good as Centaur.
The chainrings are proper machined ones, not pressed. So it's Centaur or Daytona (the old Centaur equivalent).
These are nice cranks, and the rings last ages not like the cardboard ShimaNO ones.