I've seen a pair of these on eBay some time ago, with similar stickers, described I *think*, as designed by Kerttu Nurminen. There was no reference for the attribution to her, so I'd take it with a pinch of salt.
I've a similar sticker on a Bj√∂rn Weckstr√∂m vase, in production, I believe, late 70s/80s - not particularly helpful, I know, but maybe a clue!
It's difficult to read the bottom line in the photo, but is it "W√§rtsil√§ Finland"? If so, that would at least suggest production pre-1988, when W√§rtsil√§ ceased to be Nuutaj√§rvi's parent company, after the merger with Iittala. I've also a Tiina Nordstr√∂m paperweight, with a similar sticker. She only designed for them from 1988. The bottom line on that one reads "Made in Finland" - I'll post a photo when my camera has recharged.
[Edit: photo posted below]