MICROSCOPE OBJECT MARKER ANTIQUE 20MM SCREW THREAD ZEISS, REICHERT, LEICA?

Object marker. Ink goes on the circle, the part is rotated in position and lowered on to the area of interest.  The front can be pushed in. Inside is a spring.
This part is in good condition. Can’t figure out which microscope this goes to or what it is used for. Has a 20mm thread at the rear. It is 37mm in length.Show some surface wear on the metal. It shows no dings, no dents, minor scuff marks.