Model: Carrera Reference: 3647S Date: Circa 1970 Movement: 17-jewel Valjoux manual wind, column wheel chronograph, signed Ed Heuer & Co SA on the bridge Dial: Silvered 'eggshell', applied polished baton hour markers, raised outer black 1/5th second divisions with luminous dot 5 minute markers, sunken subsidiary dials at 3 and 9 for seconds and 45 minute recording, polished pointed baton hands with luminous inserts, black centre chronograph hand Case: Polished round, screw down back, crown flanked by twin pushers Strap/Bracelet: Brown leather Buckle/Clasp: Steel buckle Signed: Case, dial & movement Size: 36mm