Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia And Soviet Union - 1931, Airship over the Arctic Region, 50k dark gray blue, error of color, right sheet margin single with comb perforation 10½x12, horizontal watermark Borders and Rosettes, nice centering, full OG, NH, VF, L. Hovest certificate, C.v. $900, Est. $600-$700, Scott #C23a