Deagol,

in your (excellent) bibliography, you list OP 1915 as having three impressions (1915, 2 in 1916), each indicated on the label of the front cover.

This eBay auction is a 1930 impression (also notes a 1924 impression) with a label on the front cover that does not seem to indicate any impressions.

The photos are poor (not quite "worst" caliber since I can read most of what I need to) but it seems an accurate listing. Were they printing this book into 1930? Time to check the impression page and not just look at those front cover labels...

Jeremy