Excellent work with the Sanborn maps,
Lorendoc. It's interesting that bring up the topic of houses being divided into apartments the day after I found the picture below. It shows 4616 Franklin Avenue in 1925. Various property websites list the build date as 1908, so it was already 17 years old.
USC Digital Library
The current view below shows two distinct entrances, 4616 and 1618, with the one on the left being twice the size of the one on the right. Then I went back to study the picture above. The long, narrow entrance struck me as a little strange when I first saw it. Zooming in, I could read the number above the door as 4618 (as it is today). I think the 1925 entrance to 4616 is set back and hidden by the window, and has since been brought forward to be level with 4618. What I don't know is whether the house was built as a single dwelling or two apartments.
GSV