Thanks guys!
I posted some
"behind the scenes" pics over on PuppetHub.
TheCreatureWork, the glasses are carved from wood (balsa), sanded, and almost endlessly sprayed with black Plasti-Dip to give a more plastic look. The puppet was meant to be mainly for display, otherwise I probably would have had to make them from a more durable material. But balsa served the purpose this time, was very lightweight, and the glasses fit Spike perfectly.