Right rear end is also Cortina . The rubber hanging out is the remains of a towing assister ring. That would definitely help with banging as theses axles are very pron eto winding up the diff and hitting the chassis rail with the nose cone. Especially so if the rubbers are shagged in those arms. As an old time mechanic you'll be aware of the reputation of Cortina void bushes. My recommendation is to replace all bushes with urethane EXCEPT for those either side of the diff which need replacing with heavy duty / estate bushes which don't have a void . You have to keep one end rubber in there as the arcs of travel conflict and will bottom out so still making it jarr.