Gold Hunter Centre Seconds Lever

A large early 20^th Century English centre seconds lever in a gold full hunter case.  Gilt three quarter plate keyless movement with going barrel. Engraved cock with polished steel regulator, compensation balance with blue steel overcoil hairspring.  English table roller lever escapement, screwed in jewelling.  White enamel dial with centre seconds, Roman numerals, blue steel seconds hand, gold hands.  Large plain 18 carat full hunter case with gold slide in the band to stop the balance.  Plain gold cuvette, maker's mark "B.B" in an oval and number corresponding to that on the movement.