Lommers microscope sample stage and focus
The focus mechanism is rack & pinion. The rack supports the microscope body, which moves relative to the fixed stage.
The sample stage is fixed to the main support pillar. It consists of two parts: The lower section has a machined groove inside the opening. Probably for a glass insert. Two friction-fit accessory supports extend from the bottom. The upper section has four locating pins that match holes in the lower section. It was probably used to secure the glass insert.
Assembled sample stage. Notice how the top piece obscures access to the lateral accessory support. This suggests that the upper piece was not a permanent fixture.