I know this may sound a bit daft, but what about showing a picture of a rotary line to and iron work shop and see if it can be copied. Afer all the design is not rocket science and although you may not be able to put it down at least the basic design should be able to be achieved. I had a washing line struts made which bolt onto my balconey which i can move to where the sun is in the winter cost me 20 tl