So, the starter motor brushes went on my wife's starter motor, and whilst I'm sure they're out there (in the UK) I couldn't find a rebuild kit. I knew I had a rebuild kit for my ZX12R so I dug it out in the hope that the brushes might be the same size. It turns out the entire brush plate is identical, and the seals are all the same. The only thing that was different was the bearing, but I didn't need that, so all was good. So it looks like that brushes and brush plate is common to a few bikes. FYI in case you get stuck.