11 Ott PAUL BUHRE D. U.
CASE . Chrome plated , 33mm .
BACK . Screw , steel .
Shows , from top to bottom : “stahlboden” , “wasserdicht” , “incabloc” , DU and the S/N .
Inside , the brand name is reported .
MOVEMENT . AS 1130 , anonym .
PUNCHING . D. U. only .
writing and number are small and uniform (1mm) . D.U marks are quite large (3mm) .
S/N : The number of registered watches (3) does not allow to define a possible range .
However , all three watches have a 5 digits S/N that begins with 73XXX .