Disk on the left side of the camera which holds the mirror spring.

In the Mirror Housing, under the ground glass these 3 screws holds the mirror lever.

The Mirror mechanism holds the mirror until the release knob is tripped. The spring pulls the mirror up and the shutter moves along the film. After exposing, the mirror has to be brought back in its position by the  Mirror setting lever. This is a safety device that prevents the winding of the shutter curtain until the reflecting mirror is depressed, thus preventing the possibility of fogging the plate or film.

Brought to you by Jo Lommen Cam