1955, North Pole - Moscow Flight, red overprint on 1r multicolored, horizontal pair, left stamp has no dash in front of Moscow variety, full OG, NH, VF, Est. $150-$200 (Image)

1955, North Pole - Moscow Flight, red overprint on 2r black and yellow green, perforation L12 1/2 instead of comb 12x12 1/2, unfolded block of four, bottom left stamp has no dash variety, full OG, NH, VF and rare multiple, Est. $2,750-$3,250 (Image)