Got the first piece of the costume in the mail today. The "girth belt". Turns out this has something to do with horseback riding, and I had to order mine from Dover Saddlery company. All I have to do is dye it a rusty red color, and devise a way to buckle it in the back. Originally I found articles on dying it with fabric dye, but further research reveals that this rubs off on your armor! Someone discovered that Red wood dye actually works better. So I'll be getting that soon.
Are you afraid of the depth I'm willing to go to for this, yet? I am. But it will be SO worth it.