I am fairly new to identifying CI but from what I have researched on this site I believe these are BSR century's. These are my moms pans shes asked me to clean up for her once i built the e-tank. As i was cleaning them up, i noticed something i'm curious about. She has two #5's and one #7. The 7, and one of the 5's has a smooth cooking surface that appears factory ground. The other 5 has more of a sand cast surface more resembling new Lodge stuff, just not as rough. All the markings on the back are identical. Only marking I could find different was a #4 casting into the hanging loop on the smooth surfaced #5. Would the smoother centuries be made early in the run and rougher one later?