I decided to buy a set of Harris clipons as they are used by the Honda TT Legends team. They informed me that they use the Harris clipons but use their own custom bar which supports the stock bar ends. I decided that I would do something similar. As my bike is largely used on the road, I decided bar end weights rather than nylon bungs would make sense. I contacted R&G and as always managed to provide invaluable assistance. They identified a set of bar ends that were a perfect fit to the bars.
Thanks again R&G!