Jerry England came up with this 1952 aerial photo of the Lower Iverson Movie Ranch, which has proved to be an invaluable resource. It's not as clear as we would like, but it's the only "map" of its kind that has surfaced from the filming era depicting the Lower Iverson.
Among other things it shows the location of Iverson's Western town, sometimes called El Paso Street or Iverson Village, toward the top right corner, just below the 118 freeway (approximated by the thick black horizontal line) and just west of Topanga Canyon Boulevard (approximated by the thin black vertical line). On that site today is the Indian Hills Mobile Home Village. A number of researchers have had a hand in identifying landmarks on the aerial shot, with special thanks going not only to Jerry England but also to John Emmons and Bill Sasser. Click on the photo to enlarge it.
A similar shot exists of the Upper Iverson, but it is much less clear than this one. I'll post it at some point, but so far I'm stalling because it's just frustrating to try to find anything on it.