Stop. You’ve entered a realm for which you cannot explain. You’re circling the rabbit hole. Take caution. In the very near future you will shank with your hat off. And at that point young sailor, you will be looking at the grey sky from within the rabbit hole.
You can stamp over it and just make a non descript pattern, you can hammer it out to lessen it, or you can grind it out. Obviously the last two will cause damage to the head and finish that will probably be far worse than the original stamping.
Probably easier to just live with it, or change his name!