I have rebuilt these Kodak drums by getting the drum to over solder melting point and brushing the infilled solder out. Where it is too shallow to mark with quik-fil, then just over engrave and be done with it. Someone from the Kodak Camera factory told me how/why they did it some years ago. It was a carry-over from their camera making days (He also told me that KL wasn't a variation of Kershaw but Kodak from Welwyn) where it was a method of marking the thin sheet brass/steel camera bodies where they couldn't engrave deep.
It's correct too..... Have a look when you see an old pre or just post war Kodak camera