Cartier 18ct gold 'Tank Basculante' manual reversible gentleman's wristwatch

the 20mm white enamel dial with Roman numerals, black inner minute track, blued-steel hands, the hinged rectangular case designed to pivot within the rectangular backplate to conceal the reverse brushed-gold dial, each with crown at 12 o'clock, nickel-finished lever movement and bimetallic compensation balance, brown crocodile leather strap with 18ct gold Cartier deployment clasp, dials and deployment clasp signed Cartier, Ref 033181, width approximately 24mm