First - I was wondering, when disassembling, if there was a good way to tell if my signal was originally painted, or bare aluminum. I saw the following, and am thinking that my signal was originally bare:

Second, I noticed some kind of mounting tabs on the insides - in the picture below, it's the four visible horizontal "ridges". There's four around each light hole.

Thoughts?
Thanks!
-Mike "Getting Ready to set the sky on fire!"