BSR century question

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?

heres the number in the handle

Most skillets look alike from the top. Photos for ID help need to be the entire bottom of the pan including the handle.

heres the bottom of the pans

Yep, both Century, after 1967 with "MADE IN USA". They were offered in both "natural" and "polish" finish (at about a 25% premium), so you have one of each.

thanks doug!