Well, adding an entire new skin involves quite some steps and in that process quite some can get wrong. Without details no one will be able to give you any more advice on what to do. I see it shows up in the parts selector, that's a good sign If your texture file assignation is right and no other flaws hit your game (notexture stuff - nomaterial stuff) then I'd clear cache first. Careful though if your mod still sits unpacked in your user folder, it might get cleared as well.