Stephanie Lees' book "Semi-Precious Salvage".
"Firefly" fans in this household and for some reason I was thinking of Captain Mal when I made these ... that is probably a bit sad for a woman my age (sigh)
I am adding these pics despite their poor quality to try and show the 3 dimensional effect I was trying to create.
Hope you can get the idea from that!
And here is a close-up of my cog look-alike.