A neat and simple little item dating from 1941/42, early in the Pacific War. This is what’s known as a Cinderella. To quote Google “A Cinderella postal refers to Cinderella stamps, which are non-postal labels that resemble postage stamps but are not issued by a government postal authority for the purpose of carrying mail. Named after the neglected character in the fairy tale who was excluded from the ball, these labels served other purposes like advertising, promoting charities (such as Christmas seals), raising funds, or for private local posts. They are not valid for legitimate postage but are collected and studied by philatelists for their diverse themes and historical significance.
Kiwi Medals 