Bidspirit auction | United States
United States - 1973, Progress in Electronics, (15c) multicolored, black (engraved) color omitted (all inscriptions and denomination), full OG, NH, VF, C.v. $850, Est. $350-$450, Sc. #1502a
United States - 1973, Progress in Electronics, (15c) multicolored, black (engraved) color omitted (all inscriptions and denomination), full OG, NH, VF, C.v. $850, Est. $350-$450, Sc. #1502a