Yeah... it's starting fine
....but I still don't understand what happened. First I searched this site and was surprised to find quite a few with exactly the same problem when they had completed their clutch rebuild.
The first thing I did was check all the interlocks that go to the starter relay. Sidestand - check, reverser microswitches - check, immobiliser - check, etc.... all ok, but it still wouldn't turn over. I pulled the starter relay and ripped the cover off to check it out, all looked ok and if I pushed in the armature it turned the starter motor over OK. I figured it must be cactus and intended to order a replacement.
To satisfy myself that it was only the starter relay at fault I connected the tank back up and jumped the +12v to the starter motor post at the rear of the battery and the bike started and ran fine.
After that I tried the starter button one last time before ordering a replacement relay and the $/0%^&^ thing started, and has been working 100% ever since.
I have zero ideas as to why it would not work in the first place. I did nothing differently, it was just like it decided to take a holiday for a week and when it got back it was happy to work again.
Either way, it's all good now and all the work went well, even my first try at a brake flush.
I learnt a lot about the bike in doing the work, and will happily dig in again if (or more likely, when) necessary.