I also believe that it is a Crown on a Staff and not a hit such as damage! See edited and cropped pics below.
Frank
View attachment 902713View attachment 902714
Based on the comments up to this point, and given my limited knowledge, this is my logical assumption:
1. The crown-on-a-staff is DIRECTLY below the countersunk screw hole. That, to me, says it predates the lettered inscription. You can see that the stamping of the "0" where it crosses the crown is pressed through the edge of the crown toward the concave crown relief. If the crown came after, that edge would splay into the relief of the 0.
2. Tejaas' opinion about the design being an earlier variety corroborates with my #1.
3. The similarity of that scripted E to the master armorer's mark and its symmetry with the screwhole and edge and the linearity of it to the screwhole and crown indicate to me that it was reused. Maybe some vintage captured rifles were stripped of usable parts in Springfield and this made it into the assembly line, so to speak.
Now, for some linguistic analysis:
4. That's definitely a "10". The marking above and below the crown (the "staff") accompany the crown.
5. I'm not convinced that is a J or an I, honestly. The style of the mark do not follow the other letters. If it were a J, in that font, I think the top would be capped and parallel with the top of the R. I know the letters below it are not perfectly aligned but they are the same size. The bottom of this "J"-like letter dipping below the invisible underline is normal, but look closely at the top of the mark. What is that little thin line? Also not convinced it's a J because of the knob on the leg. Those are more typical of numbers than letters, I think. However, if it IS a letter, I think a "J" is more likely purely
due to the knob on the leg.
6. That second L, the L[sup]
L[/sup], is an overstrike. There was another letter beneath it, between the L_B. The B is double-stamped too. Note the thicker shafts in the letter. The mystery middle letter and the B could have initially been weaker stamps that were redone for clarity. I think the L[sup]L[/sup]B are initials, personally, and were done at the same time as the "10 [sub]J[/sub]R".