Yep, parts of a watch, parts from an antique safe timer, IC chips, slip rings, various road junk. My best friend used to work for his Dad's surveying company and he found some of the pieces for it on the highway.
Depending on the finish, what you want to do is make the body as cold as possible (in freezer for a day), and then take it out and hit it with a hot hair dryer, or blowtorch. The extreme change in temp will produce those checking cracks. This works best on nitro finishes.