The Prisoner, if he could have managed to get clear of the Village, as he did in Many Happy Returns,' having returned to his London home, where could he have gone from there? Not far, seeing as "they" had his passport. And yet in 'Do Not Forsake Me Oh My Darling' the Prisoner managed to get onto the continent, as far as Austria. So the Prisoner at that time must have been in possession of his passport, but one with the wrong face, hence his need for a new passport photograph. But even then the Prisoner's passport would be wrong, because the personal hand written details in the passport would not match that of the Colonel. So in all possibility the Prisoner had either managed to get his hands on a fake passport, or waited to be issued with a new one, as for the Colonel, but then that begs the question under what name?
Be seeing you