CASE  :  Chrome plated  ,  34 mm .

BACK  :  Screw  ,  steel .

            Outside shows the S/N only . Inside is punched a number  .

MOVEMENT  :  Buren Grand Prix Cal 410 .

                       The Company name is punched on the ratchet wheel .

                       Most of the movements have separate wheels bridges . However , some watches have been detected

                       with a modified Cal 410 ( single wheels bridge ).

PUNCHING  :   D.H.  only .

                     Letters are larger ( 2mm ) than numbers ( 1mm) .

S/N  :  4  or 5  digits .

         three  batches can be assumed  from the number of recorded watches ( 74 ) .

         –  4  or  5 digits . Range could be  80XX  /  167XX ;

         –  5 digits . Range could be   223XX  /  273XX ;

         –  5 digits . Range could be   291XX   / 298XX  .

NOTE  :  Batches and S/Ns are purely indicative .