I'm having a blast digging through the archives and came across a post of yours describing the evolution of Japanese metal working from weaponry to decorative art (am including the link). In the post you mention "shakudo" being a mixture of gold and copper, which made me wonder about the demon head I'm showing.

I particularly like the design of this ojime because when you pinched your fingers together in the demon's mouth you could feel the string as you slid the ojime up and down, very ingenious.