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Not British, but could it have been Micro-Ventures, one of the segments on The Banana Splits? You could also try looking on the Mouse World trope entry to see if it is listed there.
Edited by Aspectifer
The Littles?
The best character is always the one-shot disguise.
The cat on the wall makes me think of the British cartoon series Roobarb and Custard
This is stop-motion rather than a cartoon per se but Pogles' Wood? https://en.wikipedia.org/wiki/Pogles%27_Wood
Or possibly Bagpuss? https://en.wikipedia.org/wiki/Bagpuss
Not a cartoon, but your description so reminded me of Hector's House
Perhaps The Herbs or The Poddington Peas?
Bill and Ben: The Flowerpot Men?
Better dead than smeg.
For years and years I have tried to find out what this cartoon was... It was an old cartoon, people were small and lived in a garden, there was a wall around the garden and a cat that lived on the wall. It was kinda trippy, I want to say it was 1960s. It may have been British, because I was living in Canada and a lot of the tv shows were British.