Quiller Memorandum Locations?
Christoph Gogg has the suspicion that the opening scenes were shot near the different embassies in Berlin located at Tiergartenstraße and Hiroshimastraße. He is hoping to be able to cross reference this with a member of the cast. He also says that on one DVD there is a Publicity Still of George Segal which is not in the final cut of the film.

Christoph believes that the building was the Greek Embassy in Berlin. A new property was built on the space when the old property was demolished in 2012.
The short interview with George Segal in the Making Of Film on the UK DVD is filmed there too. So he presumes that many scenes were shot in this location near Tiergartenstraße.
The old Greek embassy:-

Christoph believes that the river scenes were shot at the Landwehrkanal but he stands to be corrected.
Christoph is however certain regarding the scenes shot in the baths (1.04:36) “The wonderful old bath” Stadtbad Neukölln in Berlin and provides this picture after the renovation.
