That line needed the hideous "spur" across Camden, which would have involved knocking down most of Camden. We here in Camden objected, and we are not without influence. So it didn't happen. Sorry
It would be doing the world (and Camden) a favour to demolish some parts of it. (Speaking as a former resident of Camden). If Camden had never existed, Ken Livingstone might never have got his big break in the late 70s.