I hope you can tell from the pics, but the strike-through is fairly deep and seems to show ridges (like maybe it was made from screw threads?) and doesn't appear to have affected the obverse. Since it is somewhat unusual, I thought it might be of interest to you all.
This it is more a ex-foliation then strike through. The weight, the perimeter forms of the missing part speak more about this. Also the lines see inside the missing part. This ex-foliation will continue, look at the at the line NNW.