My solution was a simple one, I'd found Honda 3/4" chain adjusters that happened to suit the10mm axle plate. Perfect!
All I need now is some spacers to that will sit outside of the adjusters.
I thought I may have had a solution right in front of my face in chopping up and utilising washers from the original adjusters for a trial fit. It seems that they're just not wide enough, however, it was worth the shot.