Quote Originally Posted by pgomena View Post
If you do copy them, you probably will have to use double polarization (lights and camera all polarized), and that may not remove all the glare from the tarnish....
Peter Gomena
Yes, you are correct, polarized copy lights will eliminate the reflections. I restore old photos and have no problem with these.

The "silvering" is the result of compression on the photo surface caused by other photos or things stacked on top of the print. This is one hypothesis I've been told. I'm sorry I can't validate this with any reference, though.