Job: Playermodel Trouble

I need a single skin slot added onto a playermodel. Right now there are two skins, and I've tried everything to implement a third. It won't work. I have the textures to be applied as the third skin on hand, and just need to know how to make it work.

The mod file, textures, and everything inside of the materials folder is a little messy due to testing. For the most part, I figured it has to do with the QC file.