Howard Marion-Crawford (Colonel Davies) and Suzan Farmer (Judy Davies) worked together a couple years earlier, playing husband and wife on No Marks for Servility (1964).
While this was the first episode of Man In A Suitcase to be broadcast in America, it was not the first filmed. It was shown first because the ABC network believed this episode had more thrills and excitement. The series' actual first episode, "Man from the Dead," was shown as number 6 (pun intended).
The destination board on the bus (Stepney, Rotherhithe Tunnel, Surrey Docks) in the final sequence suggests that it is route 82. The route started and Stepney East Station traveled through the Rotherhithe Tunnel, and then did a circle of the Surrey Commercial Docks via Brunel Road (which runs alongside the site of the Rotherhithe Gas Works) and Rotherhithe Street, ending at Surrey Docks Station.