I'm no expert, but from what I understand from a Krause catalogue:
On the side with the flower in the center (your second image, Albert's first image):
Starting at 1 o'clock and going clockwise:
The first two groups translate as "cycle".
At 4 o'clock: 15
At 6 o'clock: year
At 7 o'clock: 50
Thus cycle 15, year 50, so 1916.
If anyone knows better, please feel free to correct.
Jan
On the side with the flower in the center (your second image, Albert's first image):
Starting at 1 o'clock and going clockwise:
The first two groups translate as "cycle".
At 4 o'clock: 15
At 6 o'clock: year
At 7 o'clock: 50
Thus cycle 15, year 50, so 1916.
If anyone knows better, please feel free to correct.
Jan