The most recent issue in Poland's "historic organs" series shows the instrument in st Andrew's Basilica in Olkusz. This stamp was issued in the latter half of 2019. It is in a similar format to other stamps in the series. The instrument was built by Jan Hummel and his apprentice Jerzy Notrowski in the early 1600's. By 1972 the organ was not playable, and a long series of improvement projects was begun. This Polish organ site gives great details about the instrument, including specifications and photographs. the level of research that has gone into the reconstruction of the instrument is laudable. I must thank my friend Mark Jameson who has generously shared with me copies of the stamps, various FDC's, and some of the large folios the Polish post office has prepared related to the stamps in this series.