I'm still guessing it's a trick of the light. Let us know, would you please Zatnikitelman? I'm really curious to what you find.
As for textures, I find there are a lot of restriction free image dumps out there with mostly what you're probably looking for. Here's a useful link to the CGTalk forum; just scroll down a bit to find links to online texture libraries. Several are defunct, but there's enough there to keep you busy a while.
http://forums.cgsociety.org/showthread.php?t=77484
What I do is keep in mind the form that I'm working on, and then look for images that fit this criteria. For example, see my post on M6 in addon development on the tether-sling prototype. The textures I used in the spool/flywheel comes from drain covers, brake linings, AC covers, and old car radiators.
Looking at the textures would never lead you to guess any of these things.