I didn't know where to post these ones but as i bought them as WWI prussian when i was 16 (many years ago, no internet..bla bla). I would like to know what they really are...militaria dealer i bought them from got me with the crown..."look that's the prussian crown, same as on the belt buckle"...it was not expensive, that's why i could afford them at the time. I just found them in a box while cleaning a bit my room..
They're 1910 or a faint 1940 dated and also bear a J.21
Perhaps a kingdom in northern Europe ?
Thanks in advance for your help