Niue
1978 Coronation 25th Anniversary, IMPERFORATE $3.30 Miniature Sheet
Topic: Royalty
On white gummed paper, Mint Never Hinged
Stanley Gibbons Catalogue: #MS248
Plate Proofs or Imperforate are not listed
I believe this to be a Plate Proof. 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.