It's a decent plot and I am enjoying it - it's perfect for a rainy Saturday. But,... there is a distinct lack of atmosphere.
There is still little that suggests that this story is set in the 70s not the 40s, there is is even less that suggests a sense of place. Telling readers that characters have travelled to Vienna or Salzburg does nothing to evoke what the places look like or feel like to the characters.
I'm pretty disappointed in this regard, and I am now also wondering if this is something I somehow didn't notice when reading Above Suspicion because I had images of black and white movies to fall back on that were set in France and Germany in the 40s.
It's not that I am lacking familiarity with the look of Vienna or Salzburg, it just that I am struggling with the way that this story is told in almost exactly the same style as a story set in the 1940s. The only difference so far is the frequency of air travel and the mention of several car makes.