This cover came up at the most recent Corbitts (UK) auction – sold for GBP300. Check out Jeff Marks original research article in PNG Calling, July-Aug last year, page 10. He reckons this is example 17 – and the mystery remains…..
The attached covers are the latest two to be added to the list.
Number 16 from Cavendish Auctions in 2016 and number 17 from the Corbitts Auction in 2017.