Who am I?

SO I am finally getting some answers in my attempts to find out what happened to my maternal grandfather.  I am German, born in Germany. My mother is German and her side of the family lives in Germany. She never met her "real" father. Her parents were divorced in 1946 and my mother was never allowed to ask any questions about her real dad, named Paul Vogt. MY father had some relevant paperwork in his files, which was needed prior to him, a US service member, and my mother, a German native, be authorized to marry.  On this piece of information was a bit of information about my grandfather. Date and place of birth:  (important info). That info is 10 December 1913, in Graben/Silesia. 
A few months back I entered this information into a German database online and several weeks ago I received a letter which gave me the information that my maternal grandfather had died 17 February 1979, in Bad Munder, Germany.
I have since written the town email for that small town to ask if he had any relatives living there.  No word back. I will continue on with my quest to find out about HIM and if my mother has any other living relatives....