After some research I found that Vader has nylon straps that hold his shin armor to his boots. It's nearly impossible to find and pictures of it. The only pic I could find was in my "Star Wars: Chronicles" book, and it's not great, you can make out two straps on the boot though. I found no pictures showing hardware, so so just went with what I could find, that I thought looked right.
I also made the shin armor glossy. It's about the only high gloss thing on his ANH armor.
Here's a quick list of what I did:
• Added thin silver scratches and weathering.
• Painted a clear high gloss coat.
• Added nylon straps, tabs and buckles.
• Painted the metal, strap hardware, black.
All that's left on the boots is to weather the leather and the souls, and the boots will be done.