30 Kopeks Workers (Soviet Union, Michel number 682), a so-called extremely rare transit error, with genuine Cyrillic postmarks "PSKOW -9 8 41" in red and gray-violet, letter from the first mailbox emptying! It was forgotten to apply the new hand stamp imprint "Pleskau" from bottom left to top right! Mint stamp, envelope with heavier signs of use, signed by Dr. Schultz and photo certificate Walter Zirath BPP (2025): " ... Such "transit errors" are very rare." - Great rarity of the area.