60 Kopeck postal stationery envelope with the overprint "PCKOB / 20 kop" featuring a genuine violet hand-stamped overprint, addressed and postmarked with the stamp "PCKOB * K * 23 8 41", envelope open at the top and left side, very well preserved, photographic finding by Robert Brunel VP (2025), examined by Dr. Rommerskirchen BPP.