Allow myself to correct myself: the ‘Force directional’ post by Nitto is oval internally (same as a Nitto 262 post), your standard Nitto made Ritchey post ain’t, nor is the WCS (I think?) its just thinner. In which case the easiest way to tell the difference between the Kalloy and the Nitto is the sharpness of the head part where the cradle rests - same design but more rounded with the Kalloy version.
Nitto 65 and Nitto made Ritchey pictured for clarity.