Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Czechoslovakia - 1920, seven trial Airplane surcharges 28k on imperforate Hradcany stamps of 20h greenish blue (black), 20h carmine (black), 25h (black), two of 200h (black and brown), two of 500h (blue and greenish black), large part of OG, VF and scarce group, each one properly expertized, Scott #C3