Recasting
While I enjoyed this film for its acting and its historical interest - the phone box, the twist, etc, I was a bit bothered by the actor playing the Inspector. He was sort of bland for my taste.
I wish they had gotten Patrick MacNee (John Steed) for the part. He would have been about the right age and picturing him delivering some of the lines would have added a bit more sly humor to the whole film.