9x19mm "RM S 11 17" and "RM S 7 18"

In a recent ECRA 2018 post with a lot of food and drinks, ECRA 2018 International Meeting/Show- Attendees Post Your Photos & Comments! there was a side discussion of “RM S 11 18” round. The way it is displayed and discussed makes it clear that it is special. May I have a short story? I am going to see The Lord of 9x19mm in a couple of days in person (no, I am not driving to San Francisco), and I may have a long story there.

Both are as described in the ECRA thread. They are standard WWI production for the German army. One case was produced in November 1917 and the other case in January 1918. Both over 100 years today!