Bill,
I think you're referring to Cocopeli (spelling?).  He's a god of sexuality or libido or something like that.  I'm not sure that he's the thing on on the head.  I couldn't see it very clearly, though.
Rich

According to the little Irwin blurb on the ebay page, it's a peacock inlay, which was eventually replaced with the eagle inlay. I must say, I can't actually read it as a peacock . . .

Don't know much about the Dead, but the flute player referred to above might be Kokopelli (perhaps sometimes with one L). Dates back to the Anasazi, in what is now Colorado.

Thanks Bob; here's a pic from:
http://4dw.net/geolor/Geolors_Exclusive_Designs_Graphics_By_Lorrie.htm