CASE  .  Chrome plated  ,  34 mm . 

BACK  .  Screw  ,  steel .

           Outside reports the S/N . 

           Inside there are “rostfrei” , “stahlboden” and “edelsthal” .

MOVEMENT  .  AS 1130  punched  “zentra 344” or “zentra 8 “ .

PUNCHING  .  Usually  D.

                       Letter is larger (1,5) than numbers (1mm) .

S/N  .  6 digits . The registered watches showed a possible range between  600XXX  and  605XXX  .

NOTE  .  

            1. Three  Zentra marked “D.H.” were recorded .

                The 6 digits S/N was lower ( 347XXX – 505XXX – 529XXX) . 

                Watches were exactly the same as the “D.”s except for the back that was

                slightly different .

            2. Range is purely indicative .