This watch is an early example (circa 1953) Omega Constellation Chronometre, 17 jewels c354 movement #13911062 "Bumper" with rotor that only swings 45 degrees, bumps on a stop and springs back to starting position to wind, compared to later Constellations that rotate completely around.  It's a very interesting process which can be felt by the wearer when it bumps.  The dial has a textured, or waffle surface in satiny-silver finish with yellow gold accents including hands.  I think it one of the more interesting dial surfaces and much more interesting than a flat satin finish.  This watch shows years of careful wear with a series of fine scratches on the 2 piece case back which can be easily removed by correct polishing or left alone---the solid gold observatory medallion retains much of it's original detail.  The leather cuff has a unique design that shields the watch movement from perspiration getting into the movement, condensing on the inside of the crystal and falling onto the dial surface causing a chemical reaction that ages the dial and cannot be corrected and in many cases leads to a dial repaint.