Looks to me that the modern crimped cables were put on an old piece (re purposed). It's funny, those cables would probably hold a thousand pounds. The old rusty part could have very well been, part of a lantern, oil or candle. It's like the top that would slide up and down to cover the chimney. It could as well been a hanging candle holder (without those modern cables obviously). The way the disk is shaped, I'd lean more toward the chimney cover idea. Shaped so water would run off.