Up for grabs a very RARE and functional/wearable vintage Hi-beat diver. Longines Ultra-Chron Chronometer, ref 7970-3, cal 431, 36000 bph, from 1968. This is the very seldom seen modell with the “CHRONOMETER” text on the dial and rotor! Approximately 41 mm in diameter excl. signed crown. 22 mm lugs. …