Rhodesia 1966 9d Double Overprint Imprint Block of Eight

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.