Great job Milo! Are these meshes converted, did you use the conventional retexturization method, or did you use any feature of the Alchemy package to do this?
by the way here i send my formula to apply bump map into a texture using GIMP,
1. I'm sure you know well about these texture

2. In 'bump texture', select 'colors' -> 'colorize', and set saturation to '0' .

3. Select 'colors' -> 'brightness & contrass', set those to '80' and '74'.

4. The last step, paste that 'bump' into the 'texture', and set the paste mode in 'overlay' .

and, voila... done.
then you can continue to improve it with your own method
thank you for all of your feedback here guys.
here is the fastest method which i do using gimp.
to make texture more appear, i repeated this method twice.
but normally for character face is enough to do this method once, and then set the opacity 50% to make the face not look too bumped/shiny.
and for colour tweaking, i use pictures on internet as reference. so yeah, usually i have so many layers for different effect in different body part.
well,
i only use gimp and MUAskinner to export my texture into someone's mod.i use the original source from deviantart, i downloaded the 3d models only to taking those textures (normal & diff texture), because the extracted texture from the converted .igb is already compressed and looks jigged (not good if i modify it and MUAskinner will compress it again).