And now for the other weird part:
That's what is stamped on the BOTTOM of that very same left side cover.
Now, since to remove that sear bar to stamp it, it would require undoing that sear safety. I'm doing a WAG and saying they never restamped it because it was more of a pain in the rear to remove the sear safety, stamp, and put it back together than it was worth?
Total WAG on that...