I finished this today. I think it may just be one of my better bone-art pieces. Cow, dead of natural causes (my parents got me the skull long ago at a yard sale and I had it in storage for years before deciding to do anything with it). Use of random found objects. The gear is from a car or bike or something - not a clock, but I still think it works.
One of the weirder questions I've ever asked anyone: "What do you think the color of Time is?" I asked this to a pair of my online/AIM friends (Hello, Lilith and Laihiriel!) I got the answers of "Blue" and "Black" respectively and thought both made sense. Blue seems to be the color of "time energy" used most often in fiction/film and black has connotations of mortality (in Western culture) and that certainly relates to the inevitable march of time (also, it's a skull...)
Don't worry, I don't need that key for anything. I'm pretty sure it was for something I left behind when I left Arizona. I've kept it aside for eventual use in an art project, and here it is.