Cook Islands

1973 QEII’s Coronation 20th Anniversary, IMPERFORATE M/S

On white gummed paper, Mint Not Hinged

Stanley Gibbons Catalogue: #MS430, Value £2.50 (2013) for a Miniature Sheet

Plate Proofs or Imperforate are not listed

Scott Catalogue: #350 Value US$3.50 (2009) for a normal Miniature Sheet

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.