Does anyone know where this is/was?

As I was browsing the internet today I came across an image on this page which shows on the right a combined stop signal (A909^A) and repeater (R909^BC) along with a fog repeater (FR909^BC). I was wondering if anybody knows where this signal is/was. My best guess is that it used to be the outer home signal for West Ham eastbound, although it may have been replaced/renumbered following the introduction of the West Ham siding. Can anyone confirm? I don't suppose it's too important, it just piqued my interest and I was also going to give the link to this website to a friend and talk about that signal and what it means and I'd quite like to be able to tell them where it is/was.

Thanks!