With the model's rig just about ready I moved on to working out the textures. When making the normal map I found that the some regions were divided by seams. These seams were blended over in Mudbox, a technique I also plan to use to clean up the divides between the texture meshes, giving much cleaner result that's faster than trying to fix the seams in Photoshop.
However the normal map appears to be a little faint, but it is there and on more extreme areas such as the throat, it is visible. I am considering going back into Mudbox to bring the shapes out it might just be I need some more time working out what could be defined by its shape and what would be defined by patterns. The possibility exists of also using a displacement map so any minor changes to the geometry do not require restructuring the corrective poses.
With the above picture I tried combining a greyscale of the normal map with the texture map to bring out the features. I consider it a bit of a mixed success though, as it has also ended up making poor Four look like she has severe sunburn. Beyond that, some greenish tint to coincide with her environment and some wrinkles and she's almost good to go skinwise.
Don't mind her lack of eyes. For efficiency's sake I decided to create the texture map on a copy of Four's geometry that matches the geometry on the rigged model. All the eyes really need are a texture map with the pupil stretched across the top edge of the image file.
The teeth and claws could easily be a shader at this stage. I just need to revise how to give the transparency of the edges. The idea that I believe will work is to give a mock rim highlight. The texture files are so far somewhat large - 8192 pixels square which I will likely keep for extreme closeup shots. Smaller files can be easily created for more distant or full-body shots.
In fact I will probably need to do this, such size extends to the normal and specular maps which will eat processing power during rendering. Understanding my shots will be important in working out the correct resolution required. the current size might be too large for what I'm doing save for extreme closeups.