The presence of "PLAQU" inscription in a cartouche means fusion-based silver deposition, while the additional rhombus with "N" letter refers to galvanic technique of silver deposition.
The son of the Polish Holocaust survivor who was the subject of Roman Polanski 's Oscar-winning film "The Pianist" hailed the awards as a tribute to the victims of World War II.It has the inscription in Polish "WARSZAWA NORBLIN & Co" ("WARSAW NORBLIN & Co") inside the oval one French word "PLAQU" under the oval. This Norblin mark is a variation of the mark No.2 with the writing of "NORBLIN & Co" in two lines instead of one.In contrast to the previous mark in some cases it has a dot (! I think that the presence of a dot could be connected with the use of galvanic-based silver deposition, while the absence of the dot could be connected with the use of fusion-based silver deposition. Next mark differs from mark No.3 by a rounder shape of the oval.The academy "appreciated the fate that befell my father, the total degradation of a well-known artist under war conditions," said Andrzej Szpilman , a doctor who lives in Europe and who attended the Academy Award ceremony in Los Angeles.The film tells the story of Wladyslaw Szpilman , a Jewish pianist in Warsaw.