Bidspirit auction | United States - Modern Errors

United States - Modern Errors and Varieties - 1978, Carl Sanburg, 13c black and brown, top and bottom sheet margin vertical transition strip of five, lower stamp has brown color completely omitted and just traces of black, full OG, NH, VF and rare multiple, PF certificate, C.v. $1,750++, Est. $800-$1,000, Scott #1731a