Bidspirit auction | Air Post Stamps and Covers

Air Post Stamps and Covers - Airships Issue of 1931-32 - 1931, Airship over the Arctic Region, 50k dark gray blue, error of color on thinned (no more then 0.075mm) paper, left sheet margin single, full OG, NH, VF (LH on selvage) and very scarce, Est. $500-$700, Scott #C23a var