1966 9d Anselia Orchid OVERPRINT DOUBLE (SG 365a). Superb UM IMPRINT BLOCK OF EIGHT additionally showing OVERPRINT OFFSETS ON REVERSE. Rare and exceptional multiple with concomitant varieties thus. Photo-cert: Eichele BPB states "A possibly unique position piece." (cv£6400++). See clickable images of reverse of block and certificate below.
