Update: here is the plate. Let's hope it is accurate enough (it is not face-milled on the underside...)
A plate for holding 76 mm x 26 mm glass slides in the microscope. My first ever 'real' drawing with LibreCAD (that website has been down for two days now, so try also librecad on sourceforge).
Drawing in PDF: chamber_holder
Drawing in DXF: plate_v2.dxf