I remember them well !
Written by a couple who were New Zealanders if my memory serves me correctly .
They were pulled because they were seen to be old fashioned and behind the times as they portrayed typical middle class English families .
They jazzed them up again a few years ago to portray the world we live in now with a more modern outlook but by some different writer . I think they did republish a few of the originals a while ago as a sort of nostalgia thingy .
I learned from them. They were fine. My own recollection is that the kids were white but not of any particular class (I don't think I had occasion to learn the word 'butler'). I am now literate, so they must have done their job.