Bidspirit auction | United States - Modern Errors

United States - Modern Errors and Varieties - 1973, Progress in Electronics, 8c multicolored, left sheet margin single with tan (background) and lilac colors omitted, full OG, NH, VF, according to Scott Errors Cat. only 50 stamps are known to exist, C.v. $600, Est. $300-$400 , Scott #1501b