No worries - you are welcome.
I googled images of kosta vase - which brought up a picture (about 6th row down) of a similar shaped vase with the same cut and polished circles. Many designers use a 'theme' in their styles so I I looked a that one, which said it was by mona morales schildt - so I googled images for her name linked with kosta - and there it was. - just lucky I guess. The first vase I found was dated 1964, so whether that gives an indication of the date of yours I do not know.