Thanks a lot both!
@Kevin: I am sure you know 100 times more about paperweights than me (wherever they might come from

)
@Erhard: thanks for the lead regarding Fenne, certainly some similarities (though the proportions are not
quite right for a Fenne "egg" - the base of mine has a diameter of appr. 4.5 cm). Still the top-heavy shape seems quite close to some of the Fenne weights...
The one in the first pic of your essay
>> link does seem to have very similar colours to the petals of my rose.
The base is actually quite well finished, highly polished with a smooth edge (not a feature I have come across in Asian weights so far -- but I know very little about paperweights from India or Japan, so that may well be another possibility).
The shape of the bottom seems to be due to a repair (there is a flake missing to one side, but it has been repolished quite nicely -- otherwise it would be a perfect circle). Sorry I hadn't noticed this until you mentioned it.
I bought it from a guy well into his sixties, who had inherited a big collection from his parents, several "Bohmemian" trumpet flower weights, old or new (who knows), some Murano flower weights from the 1970s/80s, and this one.
Unfortunately that doesn't help much in attribution

Michael