Cool Rolex of the Day #833: 3009 Oyster with enamel scientific "Controlée Officiellement" dial, 18k yellow gold, 31mm. Circa 1936 : r/rolex
Bonhams : Rolex. A very rare and unusual stainless steel centre seconds manual wind wristwatch Oyster Scientific, Ref:2765, Serial No.857**, Circa 1939
Bonhams : Rolex. A stainless steel manual wind wristwatch Oyster Scientific, Ref:2765, Case No.90698, Circa 1940