Kaoko responds...
Roy Mentis from Kaoko wrote:
"From the photos you have sent, the inner bar extends past the end of the grip by the ½ inch you mention and the issue is easily resolved by simply adjusting the throttle assembly along the bar end so that it is approx 1mm in from the end of the rubber grip. This is done by loosening the clamp screws with 4mm Allen key (2008 model and I assume same on earlier models)."
This puts the throttle assembly .5 inch further out than the left assembly, but the difference isn't noticeable. Have reordered the Kaoko and will give it a go to see if this works. Will post results.