Cartier, an Art Deco agate and enamel desk timepiece, 1920s, the silvered guilloché enamel dial with

Cartier, an Art Deco agate and enamel desk timepiece, 1920s, the silvered guilloché enamel dial with black enamel Roman numeral indicators and scrolled gold hands, within a turquoise enamel border, mounted in a lobed frame of polished agate, to a gilt silver back and strut, 9.2cm diameter, signed Cartier, manual winding movement, numbered 0363, French assay mark for silver, French maker's mark MC with cog for Maurice Couet