Papua New Guinea Postage Due 1960 6d on 7½d T.1, Cert

POSTAGE DUES: 1960 6d on 7½d Type 1 red surcharge (SG D1). Superb U example with neat corner cds. A rare stamp, only 800 overprinted. Photo-cert: Ceremuga AIEP. (cv£450). See image of certificate below.