But even on a worn die, grease could fill the devices so full that nothing appears. But on this one, I'm leaning more towards die wear/die polishing altering that area where the mintmark is located. On the grease filled area, that is not full the affected areas will be part fill, that will make the devices wider than normal. I'm not seeing that on your coin. So it is more likely a polished/worn die issue on this one.