Zenith Caliber 135 Port Royale Chronometre, 36.1 mm Steel, Ultra-Rare Circa 1960

Zenith Caliber 135 Port Royale Chronometre, 36.1 mm Steel, Ultra-Rare Circa 1960 Zenith introduced Caliber 135 in 1948 to enter it into observatory competitions. The Caliber won numerous prestigious awards and prizes, including an unprecedented five consecutive Neuchâtel Observatory chronometry prizes from 1950 to 1954. In all, the movement earned 200 honors, two-thirds of which were first prizes. To this day, Caliber 135 remains a legend in Swiss watchmaking. The watch features an original and untouched two-tome silver dial. The Zenith star logo and hour markers are applied. The condition of this watch is remarkable. Case is without a doubt unpolished, the dial is perfect and original, and the case back is free of scratches with clear serial number visible. There is a small hallmark on the front of the top left lug which is characteristic of watches imported to the Portuguese market. The Caliber The design innovations of Cal 135 included a large barrel for improved isochronism and pow