The character Carl Seidlitz didn't exist.
Shanghai Express was released in 1932 and not 1933.
Harry Brandt's now-infamous 'Box Office Poison' article was originally published on May 3 1938 in a magazine called Independent Film Journal and named over a dozen stars. Here it is shown as a headline singling out Dietrich on a broadsheet newspaper in 1944.
On the train trip to Bremen, railroad ties made of concrete are visible.