I have a small collection of older books, often boy's books, from the 1890's to the 1920's with those steam pressed illustrated covers.
Bought one this morning 'The Hero of Liege' Book published for the xmas trade in 1915 and given as a xmas present that year. Subject Military aviation and the giver just graduated as a (presumeably) British pilot. The hero is of course an upper class Englishman, the villain German, in fact a German Jew as a spy and saboteur.
In the light of WW1 part two rather Ironic, but indicative of social mores of the time.
I wonder if the giver survived. His flying options were not big