1925-26, Academy of Sciences, Popov, Decembrist Mutiny, Revolution of 1905 and Esperanto Congress, 144 mostly mint stamps, including two sheets of 40 (No.339) and 4 postal history items, numerous printing, perforation and watermark varieties, nice quality overall, full OG, NH or LH/hinged, F/VF (Image)

1925, Academy of Sciences, trial printing on thick paper without watermark of 3k and 15k, complete set in unfolded blocks of four, full OG, NH, VF (Image)

1925, Academy of Sciences, imperforated right margin proof of 3k in orange brown on Goznak paper with text on reverse, no gum as produced, NH, VF (Image)