Passai?

The Passai kata's of our lineage can be a head scratcher when trying to narrow down the the origins of the Passai kata that are worked in Shorin-ryu (Kobayshi-ryu).

Kobayashi-ryu's Passai Sho is Itosu Passai Dai

Kobayshi-ryu's Passai Dai is Tawada no Passai. this kata is also known in some styles such as Shito-ryu as Chibana Passai. Miyahira Sensei referes to it as Matsumura Passai which it really is not.
Matsumura Seito has two Passai kata funny enough called Passai Sho and Passai Dai. Neither of these 2 kata are the same or are close to our Kobayashi-ryu Passai Dai. They do however share similarities like all Passai kata do. My thoughts is that Tawada constructed a Passai kata from both of Matsumura's Passai katas and/or other sources to give us our Kobayashi-ryu Passai Dai.

The question is where is Itosu Sensei's original Passai Sho?
Could it be Miyahira Sensei's Koryu Passai also known as Gusukuma Passai?

The reason for Kobayashi-ryu not using the Itosu Passai Sho is that after watching Chibana Sensei perform Tawada Passai so masterfully, Itosu suggested that Chibana start teaching that kata. Chibana learned Tawada Passai directly from Tawada Sensei himself during the three years that he studied with him. It has also been said that Chibana learned the kata from a relative of his.