Quote Originally Posted by Sirius Glass View Post
They look like the Grafmatic flim holders however the holders are missing a loop. The fourth photograph is of a Grafmatic Septum. See http://graflex.org/speed-graphic/acc...html#Grafmatic
It's just coincidence, some film inserts to adapt plate holders for film use do look similar to Grafmatic septums because they have the same purpose although are used in a different context. These ones are just very common 9x12 dark slides (film holders).

This is the sticky thread Greg mentions.