I'm not sure I've come across an answer, but why exactly is Wensleydale called as such? Will we find out or is it one of the mysterious naming convention thingies of the Them?
The family name was Wensleydale… As it explains in the book,
‘My father says there’s no such thing as witches,’
said Wensleydale, who had fair, wavy hair, and peered
seriously out at life through thick black-rimmed
spectacles. It was widely believed that he had once been
christened Jeremy, but no one ever used the name, not
even his parents, who called him Youngster. They did
this in the subconscious hope that he might take the
hint; Wensleydale gave the impression of having been
born with a mental age of forty-seven.