These are NOT examples of the 1901 BNG die proofs. They were produced for the 9c PNG lakatoi 75th. anniversary issue stamp.
The original BNG due proofs or stamps do not have crosshatching in the value tablet backgrounds or in other background areas as these do.
Similar “die proofs” were sold in a Cherrystone auction in the USA a couple of years ago where they were similarly incorrectly described. I understand they sold for around $2,300.
