The 1964 film Carry On Spying has an agent by the name of Milchmann - Milkman, get it? Who steals a secret formula from a military laboratory.
During Many Happy Returns also has a Milkman, an agent working for the village, who arrives at the aerodrome, and having made his way into the Kitting out Room, overpowers the RAF Group Captain, and takes his place as pilot of the Gloster Meteor jet.
I'm surpirsed that the Milkman was not discovered when they refuelled at Gibraltar. Indeed the Milkman did well to get away with it, I mean he could not have uttered one single word, otherwise the game would have been up, when No.6 realised that it wasn't the Group Captain speaking to him over the radio! Be seeing you.