Oh, wait, I think I got confused with the sizes you noted, Agent. Are these posters 4' x 6'? If so, they are indeed the bus shelter posters.
If not, this is where it gets confusing:
In Scandinavian countries, like Denmark and Norway, the official theatrical promotion had their character sets produced in English in 24x33 inches. The Hong Kong and Singapore versions were also in English, but in 24x36 size. The Belgian version was also in English in that smaller size.
And, not all these countries had the same number of character versions produced.
But, there could have been some commercial 24x36 versions in Britain that we don't know about. I'm still confused myself about what characters were produced for what country in what size.
Jeannie