After much farting around I finally made the effort to add a chain guard to the bike.
With very strict Australian laws, I simply had no choice but to utilise one. My greatest concern was that it needed to be a neat and tidy guard that when added to the bike looked stock.
I purchased a Royal Enfield repro guard from India as my starting point as it was a clean and simple design that was long enough to do the trick. I removed the old tabs, remounted one and made a fresh one for a mount to the left side engine cover.
I'm pretty happy with the results, with it sitting well and mounted as solid as a rock.