Unusual Swiss silver padlock-shaped pendant watch Circa 1880

Silver, gold and enamel watch with snake chain
–
A very unusual Swiss sterling silver, gold and enamel padlock-shaped pendant watch, circa 1880.  With a 140 cm silver snake long chain, snakehead end, gold swivel and key. Accompanied by the original fitted wooden box. The bow is attached with two large gold screws, a transparent back over a glassed inner back with two apertures for winding and setting, a silver inner bezel, wide outer brown enamel bezel fixed to the frame by four gold screws. White enamel dial with radial Roman numerals, outer minute divisions with five-minute red Arabic markers and yellow gold spade hands. A bridged matte gilt movement, cylinder escapement, three-arm brass balance, flat balance spring, and an index regulator.
–
Dimensions: 49 x 33 mm
–
Signed: Anonymous  Swiss
–
Some hairlines on the dial and the hands are partially replaced.