I visited Frankfurt in the 80s and while the rubble was long gone, they were doing a lot of old-style stone construction to put up the old buildings as much as possible to pre-war pride.
It was an impressive sight to behold. A movie not directly in Warsaw but involving the Soviet Union, Germans and Poles, that I associate with this era and these actions: "Europa Europa".

Meanwhile what little online online I've done seems to support with the Guardian story. What was puzzling to me was that basically no one survived the Warsaw Ghetto. But as I understand his story, he and his family were in the Ghetto, were separated. He was entrained for Auschwitz, escaped the train, and was taken on by the Polish, as in non-Jewish, partisans. Then he fought with them and fought in the Warsaw Uprising, not the Warsaw Ghetto Uprising uprising. It was terrible enough what with the Russians taking on observational status across the Vistula, Stalin ordering his forces not to aid the Poles. But there was a survival rate for the Poles, and that is apparently part of his story. But he never saw his family again.