A missing royal jewel found in Germany. The Ministry wants it back

The Ministry of Culture and National Heritage requested the return of the ringing of King Sigismund the Old who currently located at the Museum of Jewelry in Pforzheim (Germany). It's a dense gold ringing decorated with a large square diamond, embedded in a intricate luminaire of a kind of milgriff and held by 4 claws. After 1918, the ringing went to the Museum of the Princes of Czartoryski in Kraków. Just before planet War II, he was hidden in the palace in Sieniawa. However, as early as September 1939 he fell prey to the Germans and for many years his destiny was unknown. prof. Ewa Letkiewicz from UMCS in Lublin discovered it in the Schmuck museum collections in Pforzheim. The basis for claiming the return of an object is documentation concerning its fate. In this case, only a image of the ringing from the 1930s was preserved.