This is a screen for Rolleis that did NOT have a removable waist level finder. It was installed in a camera but I ended up getting a different Rollei so I pulled it out. Comes as new, I did not need the spacers that he included.
This is his MPD screen with a grid and a split image (on an angle) surrounded by a Microprism ring. Here is a link to his site: https://rickoleson-brightscreen.com/