Gender: boy
There were a number of R. Grynbaums but only one boy fit the years 1921 and 1927. His name was Rafal Grynbaum born 1926 and he lived at SIEGFRIED 26 flat 8 and P.O.W. 44. I'm not sure what street P.O.W is. He also appears as Rajal Grynbaum born 20 July 1926 with the same information.