I'M TRYING TO CLEAR UP WHAT IS FOR ME A VERY CONFUSING ISSUE, THAT OF THE DIFFERENT DQ CASES USED ON WATCHES SUCH AS THE ALL IMPORTANT A404 SHOWN HERE IN AN IMAGE.
SMITHS DESCRIBED THE CASES USED AS NEW MODELS AND SLIMMER IN CONSTRUCTION POST EVEREST.
THE EARLIEST PRE 52 WATCHES HAD A CASE SIGNED AND NUMBERED ON THE OUTSIDE WITH A SOLID DUSTCAP. MOST OF THE PLATING IS BRUSHED MOSTLY MATT APART FROM THE "BEZEL" AREA, AND SOFT. THE COMBINED RUSTPROOF AND SHOCK-RESISTING CAP SOON CHANGED INTO EITHER A CRUCIFORM CAP, ALLOWING EASIER REGULATION, OR TOOTHED RING AS PER MANY 40'S MILITARY WATCHES, ESPECIALLY AS THE CAP WOULDN'T GO OVER THE 27CS MOVEMENT WITHOUT INTERFERENCE. MOST BUT NOT ALL DQ CASES REQUIRE A SMALL STEEL RING UNDER THE DIAL, STEM CLEARANCE WILL BE AFFECTED WHEN NOT USED IF NEEDED. OVERALL CASE PLATING IS GRADUALLY IMPROVING BY 53.
THE SECOND TYPE CASE SIGNED AND NUMBERED INSIDE USED UP TO '53 AT LEAST SEEMS MUCH THE SAME THICKNESS WHEN MEASURED FROM THE OUTSIDE, AND IT'S NOT UNTIL ABUT 55 THAT THE CASE BACK SEEMS SLIMMER. BY NOW PLATING IS HARD NOT AS BRUSHED ON THE SIDES, BUT POLISHED, IT IS JUST THE BOTTOM OF THE LUGS THAT SHOWS SOFTER PLATING AREAS AND THE CASES ARE STILL PRONE TO CORROSION NEAR THE THREADED AREAS.
THE THIRD TYPE IS A DIFFERENT CASE ALTOGETHER, AND WAS UNDOUBTABLY CHEAPER TO PRODUCE, UNSIGNED AND NOT NUMBERED, POSSIBLY BY ANOTHER MAKER, AND BETWEEN '54 AND '59 SOME EXAMPLES HAVE THE WATERPROOF ANTIMAGNETIC MARKING ON THE BACK OF THE CASE, POSSIBLY INDICATING TWO DIFFERENT CASE MAKERS. I WOULD LIKE TO THINK THAT THE LATER CASES ARE AT LEAST TO A DENNISON PATTERN. BY 59 THE PLATING WAS HARD ALL OVER AND STILL PRONE TO CORROSION AND ONE EXAMPLE I HAVE THE CASE IS EXCELLENT BUT THE CHROME JUST PEELS OFF THE BRASS.
PERSOALLY I FIND THE C'55 CASE A GOOD COMPROMISE, AS THE EARLER EXTERNAL ENGRAVINGS TEND TO ATTRACT DIRT, THAT IS IF YOU WEAR THE WATCH!