[alantf]

Nut rattling around inside the bars? Just a thought, but how about the cylinders of expanding foam you use for D.I.Y. around the house. Do you think it would be possible to shove the long tube that's fitted to the cannister, down the tube & give a short blast. When it sets it should stop the nut rattling. I've never tried it as I managed to get the bits out with a wire coat hanger, but I suppose that it should work.