Tissot - A steel 'Navigator' chronograph wristwatch

Tissot - A steel 'Navigator' chronograph wristwatch,

circa 1973, reference 45 501, circular 'reverse panda' dial with white batons and hands, orange chronograph sweep, orange minutes sweep, subsidiary dials for running seconds at 9H and hours with orange hand at 6H, date window at 3H and outer tachymetre scale, 17 jewel Lemania mechanical automatic movement calibre 1341, with start/stop and reset pushers above and below the crown, cushion shaped case, 40mm wide, to a black strap with pin buckle