I have several chips like that. I think many of them have the reeded or knurled edge (although I have some round and square edged).

I don't know what's involved but I do know that Jim Blanchard told me that all reeded edge chips are USPC. He mentioned that Burt did not have the equipment to produce such chips. They were much more difficut to produce.

The only reason I gave any thought to cleaning off that ridge is because they appeared a bit phony. Usually if there is a ridge the chips are in near new condition when, in fact, they are anyway from 54 to 90+ years old. I like them to be in good condition but also look their age.