German WW2 labels do feature the lot number of the tungsten carbide core manufacturer.
So far I saw:
Kp (assumed Krupp)
Rö (assumed Röchling)
P 322 (?)
The main question is on “Kp”. Is it indeed Krupp?
And also the factory codes are followed by more letters (not always) like Kp.Br. or Rö.Bu., Rö.F. and maybe others.
Are these the locations?
Here an example (source internet):