Thanks, that's interesting. Such a step-up converter was something I was specifically looking for when I searched for photos of the circuit board, but I didn't see any sign of it; although I could only find crappy low-res photos that were too small to be as informative as I wanted, such a thing would usually betray its presence by using an inductor, which would be a sufficiently distinctive component that I'd still expect to be able to pick it out. I guess they must have used a switched-capacitor converter instead, which doesn't use any such easily-distinguished components.
Re originality, of course this is a personal choice, and I must admit that my views may be coloured by the 6V system on my bike, where there is
not the option of fitting a 12V generator from a later model and I wish there was
