Could you post a picture of the sreaof play please?Updating an older post - managed to get OEM brackets from this site https://www.schmiedmann.com/ - based in Denmark and about £20 delivery to UK, but literally has I think every part you could want.
Turns out it wasn't the cause of the clunk, but I think I found the culprit in a very loose rear axle bushing - about 2cm of play!
Tony.