Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - United States - Air Post stamps - 1989, 20th UPU Congress, Futuristic Mail Delivery, 45c multicolored, bottom right margin ZIP se-tenant block of four, light blue (engraved) color omitted, full OG, NH, VF, C.v. $500, Scott #C125b