Okay, where to begin? I have no idea what is actually happening in that bridge position, but the colour is similar enough to the carpet that I thought somebody had drilled a hole through at first! Whatever HAS been done there makes no sense as far as I can tell, and I doubt any mounting ring would work as it is.
Notice also that there are now two slots for pickup switchers, but too close to each other that both can actually be used at the same time. I'm also pretty certain that the pot holes have been enlarged, and very asymmetrically at that. Did the previous owner want everything placed slightly differently, and thought that this would be an okay way to go about?!
The best part is, of course, that the seller doesn't acknowledge it at all in the description.