Seat posts.

Not much to see here. You can se the difference between the top of the C-record pin (Left) and Chorus (right). C-record seems to be unique, CDA and Athena appear to me the same construction as the Chorus. These are the Aero profile. A standard model was also available with a circular cross section for the entire length of the pin.



Again from the bottom C-record (Left) and Chorus (right). A bit more to see. I have seen some eBay sellers confuse these, C-Record is the only one with an exposed binder bolt.