Ah, Jani now I see the light. Those missing letters are like zeros. They don't seem to have much meaning until you stack them side by side.

I'm going to say that you have a longarm that the owner, who was possibly a client of Franz Denk, went to Frank Denk and requested a rebarrel and that would make the Lefaucheux Variant III mate with the 10,75X52R. If the longarm experienced some kind of proof in 1902 and it is chambered for the 10,75X52R Springer Marine that might also narrow the initial date for the cartridge. Any chance you could post an image of the datastring?

Kind Regards,