The Cartier Ellipse "Retailed by Cartier" (Reference YG 9986) is an exceptionally rare, highly coveted mid-century timepiece. During the 1960s and 1970s, the master Swiss horologist Bueche Girod frequently collaborated with Cartier, creating ultra-thin movements and beautifully sculpted cases. 

  When a vintage watch carries this exact reference, it represents a piece manufactured by Bueche Girod but retailed directly through Cartier's boutique network. The dial prominently displays the Cartier branding, the movement is signed by Bueche Girod, and the case back features matching hand-stamped serials from both houses.

• The Case: Measures exactly 28mm in width by 32mm lug-to-lug (with a razor-thin 5mm thickness). It features a distinctive two-body, stepped, fluidly curved oval frame crafted in solid 18k Yellow Gold. It is finished with integrated hooded Vendôme-style or hidden lugs and a classic blue cabochon sapphire crown. 

• The Dial & Hands: A classic champagne or matte silver/off-white finish featuring striking, painted radial Art Deco Roman numerals and delicate black baton or blued steel epée hands. 

• The Movement: Powered by the ultra-slim Bueche Girod Caliber 65 (or an adapted Frédéric Piguet base)—a premium, 17-jewel manual-winding mechanism celebrated for its extreme flatness.