Could be - unfortunately, I don't have an RS grille to compare it to. One observation: From dealing with GM parts over the years, I have rarely seen a GM part (especially of any size) that didn't have a part number either stamped or molded into it, even some of the smallest and most obtuse parts (like my original dimmer switch carpet grommet I ran across the other night - has part # and manufacturer, and "Made in USA" molded into the reverse side).
Regards,
Steve