So I have recently been pondering the idea of adding an external pouch to my Gen3 pack OD green Cordura is easy enough to procure but I'm curious about the seam tape, buckles, and webbing. Are they cotton or poly? Not quite sure, also does anyone know where I could pick up a couple more of the buckles? I could make do without but would like to have the pouch match the ruck aswell as possible.