Back in “the old days” (many years ago it seems, but not all that long ago, really) when I first started watching Doctor Who, I confused “The Moonbase” with “The Tenth Planet” as the first Cybermen story. I think that’s because “The Moonbase” has all of the hallmarks of a first appearance and does such a good job introducing the Cybermen to the audience that it seemed like a first appearance to m…