NIUE 1983 Protect the Whales IMPERF Plate Proofs, Set of 9 pairs

Description

Niue
1
1983 Protect the Whales IMPERF Plate Proofs, Set of 9 pairs
Pairs from the right margin of the sheet
On white gummed paper MNH
Stanley Gibbons Catalogue: #487-95, Value £37.70 for normal stamps
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. I purchased this material from Auktionshaus Gärtner. Follow this link for a 10 page article on the Fournier Archive and modern stamp printing
http://fipthematicphilately.org/documents/Articles/The%20Fournier%20archive.pdf