The Papua Lithograph Series(.pdf, 791KB)
The Large Papua Lithograph 2s6d discussion(.pdf, 592KB)
Understanding and identifying the 3d Bi-coloured Typographs(.pdf, 1.95MB)
The "tail" flaw [39] of the 1/- Harrison Aeroplane Overprint in Deep Carmine-red - NEWLY DISCOVERED(.pdf, 674KB)
The "tail" flaw [39] of the 6d Harrison Aeroplane Overprint in Deep Carmine-red - NEWLY DISCOVERED(.pdf, 3.3MB)
A review of prices achieved over the past 12 months for the aeroplane overprint varieties(.pdf, 1.12MB)
Analysis and discussion of the OS Official Mail perforations and their varieties(.pdf, 91KB)
Analysis and discussion of the stamps of the British New Guinea issue and the Papua Overprints(.pdf, 1.19MB)
Defining paper thickness and methods of identification of stamps issued by De La Rue (BNG)(.pdf, 970KB)
Further discussion by Bill Gammage on paper thickness and annomilies of the stamps issued by De La Rue (BNG)(.pdf, 970KB)
Plating Flaws by A.A.Rosenblum of the:
