Code on Parts Packaging

I have a milled follower that came in this 1965 dated wrapper. I am going to assume that it is a re-pack. They weren't still producing milled followers in 1965 were they?

The question that I really have is, can anyone tell us what the RK RGB on the packaging stand for. I also have some parts with RK HRH QC, RK S/B QC, and RK HRH (no QC ).

Thanks, Greg V

It is a repack. RK was Rock Island.

I do not know what RGB stands for.