Courtesy of Kyle Graham at Concurring Opinions, I have some new info about the location and photography of the phone booth from Katz v. United States.
First, tune to 0:49 of this video. You will see a block of three phone booths on Sunset Boulevard in 1967:
Here is a screen-shot.
And from “Every Building on the Sunset Strip” published in 1966 is this picture (on page 9):
Only one phone-booth is visible. The opinion in Katz mentions 3 booths. So it was either cut off, or two were added. I think this is it!
The present-day location is at 8210 Sunset Blvd. Alas, the phone booths are gone.