just took a second look at this one. this coin looks similar to the 17S. take a close at the area in the rays to right of the L, there might be some residual tape like on the 17S there that crossed over the thigh and onto the rim at K2.
it was actually not uncommon back in the day for someone to put a heavily worn coin like this in like a whitman folder and tape it in to keep it from falling out and would explain why we are seeing it only on the obv. this one I might consider leaving alone. just pointing it out