Thanks for the help, guys. I'm completely open-minded on this.
How contemporary is "contemporary"? I know where this has been since the late 1970s (although it was in someone else's house, not mine).
The base has a good amount of wear, certainly comparable with pieces I have from the 50s. This appears genuine and random rather than "helped along" with sandpaper or such like.
Might vases such as this have been coming out of Poland in the 50s or 60s?