Pin

Thanks to Vanalom for the picture on the left!

That's the best I can do to help you figure out the size.
It's not exact, but it's a rough estimate!
(not to mention humorous in a rather demented way)

Sculpty

Click either picture for larger view

Create a metal base with wire and wire mesh or use a belt buckle and then fill with sculpty(or other bake in the oven clay). Carve in design

Bake and spray paint gold -though it may be silver, it's hard to tell. I went with gold to match the armor.