It's finished as far as fixes are concerned, but I had a look at my level-adjusted version on my laptop and the noise in the blacks is horrible - not that this matters on most display devices, but I'm sure it's not doing the encoder any good. So, I think for this and other reasons I'm not going to bother with the global level adjustment - viewers should have the ability to alter the levels on whatever their playback device is. As I think I mentioned before, it's probably also introduced some colour banding.
I've finished re-rendering the PAL video, and the NTSC video is running now - then it's just a case of tweaking the chapter points from my old project files, and I'm done.