Hey,
Welcome. It is Finnish, the single crown tells that, see
Finland Date Marks
If it were Swedish, it would have a triple crown mark, see
Sweden Date Marks
I'm pretty sure that "Warman's Jewelry" by Christie Romero, shows your KK maker's mark as the firm of Kaunis Koru. (can't seem to find my copy in the mess)
Hope this helps.
Fin