There was a popular song in WWI or two. The soldier claiming the deck of cards was his bible, his almanac, and I believe a few more things. It tells a good bit of history too.
Those cards aren't the oldest version, the oldest ones were rectangular and had white backs. There were always playing cards laying around and those white backs were the original calling and business cards.
Those corners look to be cut after leaving the factory, maybe a shaved deck.
Another bit of trivia, the kings, queens, and knaves represented real people. I forget the kings, none were arthur. One of the queens was said to be Joan of Arc despite her never being a queen that I remember. One of the knaves, later jacks, was lancelot, the only camelot charactor in cards. The knave went away first in the US where cards were often called by their first letter. Two k's were awkward.
My trivia for cards other than Titanic always called one the suicide king because of the sword pointed at his head. Might have been common parlance in his day.
Hu