The fake briefcase contains all the James Bond stories in stead of secret electronic equipment. Both director Peter R. Hunt and actors Roger Moore and George Baker were involved in James Bond movies.
In the German version, Schubert's name was changed to Brahms, for no known reasons.
All the James Bond books clearly are uniform in their cover design except On Her Majesty's Secret Service. This obviously references the film since George Lazenby's picture is on the front cover. The film was directed by Peter Hunt and featured George Baker.
Tony Curtis and Suzanna Leigh also played a romantic couple six years earlier in Boeing Boeing (1965).