Bidspirit auction | Soviet Union - Stamps and

Soviet Union - Stamps and Postal History - 1926, definitive issue, imperforate plate proofs of 8k on chalk-surfaced paper, considered to be proofs of 8k stamp on improved paper (Standard Cat. #0121), five vertical gutter pairs in carmine, orange, yellow green, light blue and magenta, full OG, NH, VF and rare in such format, Est. $2,000-$2,500, Scott #283