Well, Dorian obviously got bored of hearing me moan about how I couldn't get the wrecked gearbox sprocket off (I did try a bit, honest..) so when he was over the other week he stole the motor and took it into his workshop. One proper pull on a proper puller later, and the sprocket is off. At last! And though Dorian is not rebuilding the motor for me, he reports that "The engine itself is in a very poor state. I don't think I have seen one with this much wear for a long time. The oil pump fibre gear is totally knackered and you might have problems getting one. All the shafts have huge amounts of play and I imagine it can't be just bearing wear. A bit of engineering might be needed to sort this one out...."
Sounds ominous, and expensive too. Watch this this space, or buy the previous issues of the mag to see how the bike arrived to this point