Aitutaki (Cook Islands)
1984 Christmas IMPERFORATE Set of 4
Singles from the bottom right of the sheet
On white gummed paper, Mint Never Hinged
Stanley Gibbons Catalogue: #509-12
Plate Proofs or Imperforate are not listed
I believe these to be Plate Proofs. The printer of this stamp issue Fournier S.A sold its philatelic archives of stamp artwork and proofs in 2007 through the German stamp dealer and auction house Gärtner.