30 K. Workers (Soviet Union Mi.-Nr.682), extremely rare so-called unsurcharged usage, with genuine Cyrillic "PSKOW -9 8 41" cancels in red and grey-violet, letter from first collection from letterbox! New "Pleskau" handstamp overprint, normally applied diagonally from lower left to upper right, was omitted! Stamp sound, envelope with substantial use marks, signed Dr. Schultz and photo certificate Walter Zirath BPP (2025): "...Such unsurcharged usages are very rare." Major rarity of area.