They may headspace perfectly but it depends where the initial tenon thread begins (clock position) that determines where the stamping position will be on different receivers.The one thing I remembered today when I torqued my barrel onto my action is that the caliber and twist inscription is upside down when the barrel is torqued. Kind of bothers me a little inside
I'm far from a gunsmith, but it seems that with a headspaced barrel it would be easy to tell where it was going to end up.
The rest seems good so far.
That's why most prefit companies stamp all around the shank.