The stage is attached to a sleeve that moves up or down when the focus knob is turned. A threaded shaft descends from the knob to a spring-loaded crossbar located inside the main pillar.
The focus knob (arrow) is placed at the top of the main support pillar. The microscope body was supposed to slide in the outer mounting sleeve for coarse focusing.
The mirror has one reflecting surface (parabolic, dia=2.9cm). The gimbal is fixed to a collar (arrow) that is placed on the lower part of the support pillar.
The mirror and attachment collar.