Swiss steel pocket watch with split seconds chronograph Circa 1958

Observatory chronometer with 21 jewels
–
A tested observatory chronometer with split seconds chronograph, made by Longines in Saint-Imier, Switzerland, circa 1958. The numbered open faced case of this watch was crafted from steel. The original silvered dial has Arabic five minute and hour numerals, a subsidiary seconds dial at six o’clock inscribed with Fab, Suisse, a 30 minute counter at twelve o’clock and blued steel hands. The numbered movement has 21 jewels, an anker chronometer escapement, a fine adjusting device and a split seconds chronograph.
Case and movement have matching numbers and dial and movement are singed.
–
Diameter: 66,5 mm
–
Weight: 267 g
–
Signed: Longines
–
The watch was tested at the Neuchatel Observatory in 1958, chronometer certificate is included.