Tac,
Thanks for the very interesting explanation.
I wasn't planning on sticking any of this old material in one of my lugers.
As I said, I had heard stories of Dutch abuse of the British 9mm rounds in the wrong weapons. Your explanation seems to fit the bill perfectly!
It also explains why there are so many Dutch lugers with a mismatched toggle/frame assembly. As there are 2 rounds missing, this box probably killed two pistols
Any additional info on the 'Z' maker's code?
This stuff must've been popular on the surplus market