What's the name of the mysterious Christmas card couple?

[elliollie]

I can't remember the story? Is it a joke that people play or did it start as a genuine mystery?
You know the one where a Christmas card arrives every year and nobody knows who the senders are. It was something like Christine and Bill or Sally and Richard or something...

@Aycharow how lovely of you to have tried so hard to find them. Especially in the pre internet days. I know what you mean about being sad when they stop.