Fixing the skin issues...

I became frustrated with the botched reasult and asked the tutor for help. It transpired that I'd somehow managed to move the skin image on the Unwrap map causing a misalignment when it was applied to the model.

This was rectified by moving the 'skin' back to the side until the features lined up.

The material was then reaplied as a Bitmap and this was far better..... The hair in particular is much more realistic.

By switching back and forth between the Photoshop Image and the head model, I was able to make adjustments to areas that didn't line up. The eyebrows sat too low, the lips were too wide and the eyes weren't quite in line. Luckily the software packages acted 'parametrically' meaning that updates happen in the model when it was moved so long as the Photoshop image was saved.