The Lady From Shanghai - On The Lam - Grant Avenue from California to Clay
Then ... O'Hara passes by the China Herald office and we see the west side of the 600 block of Grant Avenue filmed looking south from the Sacramento Street junction toward the Sing Fat building at California Street (map). (Oh no, not another Chop Suey restaurant!).
... and Now, interestingly, the scene above must have been filmed in the studio with the backgound projected behind a foreground set of the window otherwise the angle constraint inside a store would not have revealed that extended street view.. Welles often used such combinational tricks for a richer visual effect.
Then ... O'Hara passes a corner store but which junction is this? Let's look at the clues - the lamppost tells us he's on Grant Avenue, and he's crossing over cable car tracks. That's a start.
... a vintage photo ... this 1935 photo nails it - note the identifying corner with checkerboard tiles. The store is at 801 Grant on the northwest corner at Clay (map). We can also see the low rooftop opposite where the camera for the movie view was positioned, behind the adjacent street lantern dominating the foreground above.
... and Now, the same corner taken recently. See how its awning wraps around the lamppost, as it did then. There's no cable car line on Clay now, it was shut down in the 1940s.
... another vintage photo ... just to be really thorough, this 1940s photo captured the same corner, viewed the other way, with a cable car passing by. The store with the checkerboard tiles is at left and the (camera) rooftop is across Grant.
Then ... O'Hara continues north from Clay, closely pursued by Elsa. These two captures show each of them near the Chinese Pagoda, a cocktail and cafe place at 830 Grant (map). For the Elsa shot Welles used the same window-in-the-foreground studio trick as above at the top of this post. (In a variation on the theme, the Chop Suey on the Almond Cookies sign is a sundae ... ugh!).
... and Now, this recent photo spans both of the backgrounds above. Elsa was opposite what is now the Peking Bazaar and O'Hara was passing an optical store now occupied by Dee Dee Facial at 814 Grant.