Well, I couldn't resist. I was wandering the stacks at the California State Library in Sacramento when I spied a nice run of San Pedro city directories. So I was on the floor for an hour taking notes.
The new San Pedro and Wilmington Theatres page is the result. I also explored the Cinema Tour and Cinema Treasures listings for the area and collated their data with info I had from the library.
Except for the Granada in Wilmington and the Warner Grand (shown here in a 2007 view) it's all gone.
Photos of the vanished theatres seem to be scarce. Let me know if you're aware of any I missed.