So this morning off it came again (happens every couple of weeks ), but as it is modular I needed to take off just the back half. It was reassuringly quiet as I shook it. So heatshield and dome front off and exhaust back on.
Result was perfect. No rattle and everything nice and solid. The heatshield has suffered a lot over the years, it is full of holes where we have tried to secure the domed front end, which was a terrible design and just held in place by being squashed by the heatshield, so it was looking decidedly scruffy,
As you can see from the picture, it isn't as 'flash' as when it had the heatshield on but to my mind actually looks better. If I really want her to look smart I can always put on my spare exhaust which has a brand new heatshield. Another sigh of relief.