Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - United States - 1991, Harriet Quimby, 50c multicolored, left sheet margin USPS block of four, imperforated horizontally, perfect condition, full OG, NH, VF and scarce, C.v. $1,800 as two pairs, Est. $700-$800 , Sc. #C128a