15 Kop. with blue hand stamp overprint "Pleskau" from lower left to top right on marked registered cover (right clearly cut back), stamp in perfect condition condition, used "PSKOW -k 12 9 41", small issue, these stamps were unfree sells but rather authorities and companies placed at the disposal, signed Zierer and certificate with photograph Zirath BPP (2014) : "due to the all small issue came these stamps not for sale. ", Michel 4. 500.- (for cover)