The handle of the Varley Stage on this Student's microscope extends above the stage. Other P&L Student microscopes (e.g. this one) had a Varley stage with a descending control knob.
The control knob pivots from a cast iron arm and moves the stage freely in both X and Y.
Microscope slide stop at the back of the stage.
These two tabs (arrows) underneath the stage apply tension to the top plate, keeping it stable. The two white friction tabs may be ivory or bone inserts.