Right rear 1153506905
left rear 1153507305
steel, same one is used on W126 chassis. Places that sell the used usually dont know how to pack them and horribly bend the backing plate, which is a real problem that takes a huge amount of time and expense to remove. The rear backing plates are NLA so that makes it worse. That looks like what happened to the one you show on the pallet. The arm tends to rust out on the bottom beneath where the spring sits.