It still wasn't sitting right with me so I took it all off and started again:
I was starting to like the shape, especially the detail around the top of his head. Once I had put this in, the rest started to fall in place. One thing that was making it all so difficult was that I had become attached to the finished side of his face and didn't want to add or take any more clay on / away from it. Unfortunately though, the other side of his face just wasn't corresponding with this finished side. A lot of it was protruding far too much and it didn't look like the same face. So, I had to add more clay on to the finished side which would allow me to balance out the other side...
I was having so much trouble with his face around the nose and jaw area that I decided to just get rid of it and take it back down to the skull.
And that was it! I had finally finished it! Some parts were starting to crack but this wasn't a problem, I would be able to fix it just before I started to cast it and hopefully it wouldn't show up. So, here's the finished sculpt: