It all started when I was a teenager and an uncle from Saxony left me his collection of Third Reich stamps. In it, I stumbled across a series of blacked-out portraits of Hitler from my place of birth ...

"The dear and [considerate?] Rosa Nienau Adolf Hitler Munich, the 16th June 1933," he wrote. Rosa, it appears, later added her own stamp to the photo, drawing flowers onto the black-and-white image.