Postal stationery envelope 30 Kop. With advertising slogan \"used the airmail\" with red hand stamp overprint \"PLESKAU\" as in the mailbox vorgefundener letter with violet cancel \"PSKOW -a 9.8.41\", two brown spots and defects flap - otherwise pristine, very rare, signed Dr. Schulz, photo expertize Zirath BPP: \". Extremely rare. \"