This would probably get more responses in the regular JA Skinning Forum
instead of the Showcase Forum.
But anyway, I recommend that you read jp-30's tutorial http://web.archive.org/web/200304110...skinning.shtml
because it describes one way to match skin tones without losing detail. Basically you desaturate all the color out of it and then recolor it with one skin tone. Use less than 100% opacity with the color so the tonal variations show through the color.
And you don't always have to use shaders for the leathery look. Look at some of the Raven leather textures. The jedi_hf torso_a1 has a leather look without a shader effect on the leather part. There are probably others, that is the one with which I am most familiar.