Yes, what keeps the trim in tension is indeed (2) small wire hooks and a long rubber band. Most assemblies are long gone because the rubber band deteriorates and the hooks fall off. I found one from Mercedes Classic center many years ago. It is indeed 111 910 50 64. I replaced the band with a UV resistant rubber band so it might last. One hook fits in a small outward facing hole on the sliding trim. And one hook fits in a outward facing hole in the seat frame. Sorry, no pics.