Pleased with myself. The previous bracket was 2mm thick and kept bending, making it almost useless; it also didn't have a rubber stop.
So I made a replacement, using a 4 mm stainless steel flat bar and a rubber bumper from Amazon. I managed to bend it into shape in a small vice I have using a club hammer; it took a lot of persuasion.
Here it is fitted, hanging from the exhaust mounting point.
Goes to show what you can do with a minimal set of tools. :-) Hopefully useful for anyone else having to make something,