2006 rear knock, metal brackets loose?

Hello all, got a suspected accident damaged/repaired disco 3 which has an annoying knock when driving over potholes or mildly rigged terrain. I climbed under the bacl and just near the bumper alongside each side's exhaust there are some cast iron pieces with 03U0A cast on them along with the LR logo. I presume they are no aftermarket but cannot figure out why they are both loose and swing into the chassis itself. I reckon this is causing the knock. Any idea what they are?

id first introduce yourself first ^^^^^^^^^^

but id lay money on your knocking is your rear arb bushes

Hi I'm Neil, I'm a Land Rover Addict (Hi Neil...), My most recent purchase is a 95k on the clock Disco 3, TDV6 had some issues with various bits and bobs, but when driving over just a normal dirt road there is a definite metal on metal sound. Land Rover claim they can't hear it. I haven't ruled out bushes either front or back but would have thought the MOT would pick up if they were duff. What I don't understand is why these 2 metal bits swing freely right near the back bumper. Hope you can access these, I can find nothing that matches these numbers anywhere on the net.