Extremely rare German silver keyless lever watch Circa 1915

Silver observation watch by Eppner & Co. royal watchmaker
–
An extremely rare silver German military observation watch with open-face, circa 1915.
Signed lever movement with matching numbers. Signed enamel dial with Arabic luminous numerals, outer minutes track, subsidiary dial for the seconds, and luminous hands. Engine-turned silver case, dust cover with engraving; Zur Erinnerung an den 22ten Juni 1915.
–
Diameter: 56 mm
–
Weight: 114 g
–
Signed: A. Eppner & Co. Breslau