I think that's the same as mine except that my 'patch' is in the cables on the outside of the property. Slightly odd to put it there in one way though. My property has additional cables supplying it (eight I think(*)) so the outside cover plate would struggle to fit flush against the wall as it is.
Here is a photo of what was the master socket (now the extension).
(*)Actually that suggests the HH engineer might have done something with my old master. I remember now that he released the cables from inside then removed the cover outside and was horrified to see 8 wire bundles fall out in front of him. Took him quite a while to find the right pair