Martin BIRNBAUM's town of birth was called Trachenberg (not Frachenberg). It is a town in Silesia, now called Zmigrod, Poland.
His parents were Leopold BIRNBAUM and Alice BIRNBAUM geb. BEHRENDT (1881, Christburg, Westpreussen - 1944, Theresienstadt). Alice was a daughter of Aurelie BEHRENDT geb. CANTORSON (ca.1851, Christburg, Westpreussen - 1910, Breslau). [I wrote that in 2013, but now in 2021, I do not know why I concluded that Martin was a son of Alice and Leopold BIRNBAUM; he was born 2 years before they married. Leopold BIRNBAUM was born in Trachtenberg, but I do not currently see any documentation to support that Leopold was the father of Martin.]