Gold Swiss Lever

A 20^th Century Swiss lever in a gold open face case.  Gilt split three quarter plate keyless movement with going barrel. Plain cock with polished steel regulator, uncut bimetallic balance with spiral hairspring. Club foot lever escapement.  White enamel dial with subsidiary seconds, Arabic numerals, blue steel Breguet hands. Plain 9 carat open face case, gild metal cuvette, maker's mark "GS" in a rectangle.