erichard, I'd send that picture to Kahr customer service and see what they say about it.
To me that isn't a structural high wear area and I think it could just be filed or dremeled away, but that should be their call.
I've never seen one like that before, obviously a void that went unnoticed.
They may want to just replace the slide for ya or agree that it can be cleaned up.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
"If you are a warrior legally authorized to carry a weapon and you step outside without that weapon, then you become a sheep, pretending that JOCKO will not come today."