Hope somebody can advise me on this. I have a stamp which I believe to be Australia, Scott #258 (as it has the expected watermark). However, it has a straight edge like it came from a booklet, but I can't find any details of booklets in Scott or any other resource.
There was a large number of this stamp printed in booklet format. Some were watermarked and others printed on unwatermarked paper. Source is the Australian Commonwealth Specialists' Catalogue.