Gold Open Face Lever by IWC

An early 20^th Century Swiss lever by IWC in a gold open face case.  Gilt three quarter plate keyless going barrel movement stamped "IWC - Probus - Scafusia".   Plain cock with polished steel micrometer regulator, compensation balance with blue steel overcoil hairspring. Screwed in jewelling, club foot lever escapement. Signed white enamel dial with subsidiary seconds, Arabic numerals, blue steel hands. 14 carat gold open face case, the back with faint traces of engine turning, signed gilt metal cuvette.