Large Gold English Open Face Lever by Dent

A large 20^th Century English lever by Dent in a gold open face case.  Gilt half plate keyless movement, raised section to the  with going barrel. Plain cock with polished steel regulator, diamond endstone.  Compensation balance with blue steel overcoil hairspring. English table roller lever escapement, screwed in jewelling, escape and lever pivots with endstones. Signed and numbered white enamel dial with subsidiary seconds, Arabic numerals, blue steel hands. Substantial plain 18 carat drum shaped open face case.  Plain gold cuvette, maker's mark "RN" in a rectangle and number corresponding to that on the movement.