WWI Koehn (Geneva) vernier marching/sighting compass. Serial 20904 Date 1915

A good WWI Ed. Koehn (Geneva) Vernier pattern VII sighting / marching compass.
Serial No. 20904 Dated 1915. Compass lid and bezel both carry the number 691.
Made by renowned Swiss watchmaking firm Edouard Koehn of Geneva.

Mother of Pearl compass dial. Compass plate cover rotates on its bezel and can be locked. Rotating compass plate can be locked with sliding catch for transit and also has a sprung thumb lock for taking bearings. The prism has 4mm of adjustment up/down for focus. Excellent clean prism glass.

Note: Missing its cover glass plate with engraved sighting line.
(A piece of flat watch glass 36mm diameter would be suitable and easily fitted with the retaining screws)

Dimensions:
54mm diameter x 24mm
Weight: 148gm
Cased: 215gm

Excellent condition (bar cover lid glass - price reflects this). Original leather case.
Please examine photographs as these form part of the condition report. T3208