We didn't have long to look around this year as we were going out for lunch, but I did manage to buy these playing cards:
They're a novelty pack called "crooked". I don't collect these normally, but they were only a quid (although that's still twice what I was expecting to pay). They were made in Hong Kong to a British design, but were probably for an American company, A. Freed. As for the date, probably 1960 onwards.
They're impractical to use for some games because they don't line up when you have a stock face-down and the top card face-up. I won't be playing with them anyway, as they stink of tobacco. It'll be awhile before they lose that smell.
They're still something I can use to amuse younger relatives with, though, assuming they've seen regular playing cards.