Model: Carrera DatoReference: 2547NSDate: Circa 1970Movement: 17-jewel Valjoux Cal.723 manual wind, signed Heuer Leonidas on the bridge Dial: Matte black, applied polished baton hour markers, black outer 1/5th second divisions with Arabic five second markers on silvered chapter ring, outer blue calendar indications, engine turned silvered subsidiary dials at 3, 6 and 9 for constant seconds, 30 minute and 12 hour recording, day and month apertures at 12, polished pointed baton hands with luminous inserts, centre chronograph hand, blue crescent tipped calendar handCase: Brushed and polished round, snap on back, crown flanked by twin pushers, quick set buttons set in band at 9 and 10, No.11057Strap/Bracelet: Fitted stainless steel Gay Freres smooth ribbed link Buckle/Clasp: Signed folding clasp stamped '3 70'Signed: Case, dial & movementSize: 36mm