Vertigo: Hitchcock's contemplated changes

Eye contact at Ernie's Restaurant
As originally shot and edited, Madeleine in leaving the restaurant turns and looks directly at Scottie. This frame still is from the original 1958 preview trailer for Vertigo, which includes the shot. The superimposition of Scottie and the flowers (from later in the movie) was done for the preview and was never in the original scene.
Hitchcock decided to reedit the shot to eliminate Madeleine's direct look at Scottie. The shot of her turning her head is interrupted by a shot of Scottie (also turning his head, away) which elides Madeline's eye contact.
Judy's flashback
Judy's confessional flashback "solves" the mystery of Vertigo forty minutes before the end of the movie. The flashback was not part of the script until its final version. Hitchcock worried about it right up to release of the movie, and in fact tried to have all prints recalled so as to edit it out. Paramount refused, presumably because of the cost, so the flashback remained.
Judy's voiceover: I want you so to love me.. . . as I am, for myself, and so forget the other and forget the past. I don't know whether I have the nerve to try.

The epilogue
"God have mercy. . . ."
Hitchcock shot an additional scene following the climax at the tower. In a single shot lasting 75 seconds with no dialog, it shows Scottie returning to Midge's apartment, where she is listening to a radio report about the impending arrest of Gavin Elster in Europe. This scene apparently was intended as insurance against objections from the Production Code or in other countries. It may have been shown in some places, but was not part of Hitchcock's final cut of Vertigo.