Have you tried looking at an online map (MapQuest, Yahoo Maps, etc.) with satellite-photo views? That might be able to narrow down the position.

Of course, unless the original site is now luxury condos, you may still have a very distinctive (and solid?) terrain outline to make a match.

There was an interview/remembrance of Lucas using a telephoto lens to shoot across the studio lot for the white limbo interior sequences. I'd expect he'd use the same lens (???mm) for this shot (no extra rental charge).