Good job.
I gotta say, I'm a BSR guy. I have that exact same skillet, exact same markings, and it is my favorite GP user; if I could only have one CI skillet it would be that one.
I also find it quite interesting from a historical perspective for several reasons.
You can date it as being post mid-'70s because of the size marking. BSR holloware was originally sized to match stoves from Atlanta Stove Works (their parent company), and thus were a bit larger than the corresponding size numbers from other manufacturers.
That said, the standard story is that manufacturers stopped grinding the cooking surface smooth some time after they switched to automated production. But, though BSR switched to automation in 1966-1967, the cooking surface of this skillet is still ground smooth. So, this shows that BSR continued that practice well after the switch.
I also have a BSR #12 that was produced in the late '60s, shortly after the switch to automation and inclusion of "Made in USA" markings. In comparison, the #12 is much thicker/heavier and crudely finished, such as the grinding off of flashing / side gate mark. And though the cooking surface of the #12 is ground smooth, it is not nearly as well done as on this later #10.
To me this shows how BSR continued to refine their manufacturing process after the switch to automation. The early automation piece compares quite unfavorably to pre-automation Red Mountain examples, but this later #10 has been refined to the point where it much more closely matched pre-automation quality. Not perfectly, but much more closely.
Finally, the markings - it has been commented that BSR markings were inconsistent and using them for dating pieces should be more guideline than gospel. This pan shows a couple of variations from what was normal for that period.
First, it lacks "Made in USA", even though BSR started including that mark in the late '60s. Why, who knows? But it does reinforce that the "Made in USA" markings were for marketing purposes and not because of any regulation. I have a different piece of the same era that also lacks that marking, and a piece that has it.
Then, BSR is said to be unique in their use of "IN" to abbreviate "inch" and "NO" to abbreviate "number". Though this skillet uses the "IN" abbreviation, it lacks the "NO" abbreviation. Again, why, who knows? But it is another example of their inconsistency with their markings.
OK I'm spent. Hopefully you find this as interesting as I do. Regardless, hope you enjoy the skillet.