A painting by Carl Blechen, a 19th century German landscape painter, that was stolen during the Nazi era has been returned to the heir of its former owner, the Federal Art Administration announced on Wednesday. The painting “The Mill Valley near Amalfi” once belonged to Edgar Moor (1912-1994), the nephew of the brothers Arthur and Eugen Goldschmidt, two Jewish men whose art collection in Berlin was looted by the Nazis. The Goldschmidt brothers took their own lives following the brutal November 1938 pogroms known as Kristallnacht, while Moor managed to emigrate to South Africa and then eventual…