Bidspirit auction | Soviet Union Collection of Sheets

Soviet Union Collection of Sheets and Large Blocks - 1951, Nikolai Lobachevsky, 40k brown, small size stamp, folded once complete sheet of 100 (10x10), a dot inside ''C'' in ''CCCP'' (position 91), full OG, NH, VF, C.v. $475, SC.v. 30,100P , Sc. #1575, var