Hi All
Some thoughts on this fascinating thread (having just returned from cross-country skiing in Austria).
I don't know much about sulphide paperweights and related items such as beakers, plaques and so on containing sulphides (though there are some specialists out there who do know a lot), but I have seen quite a few antique French paperweights, including some from 'unknown' factories, and the canes in this paperweight do not strike me as French, at first sight. That is not to rule out France as the origin, but I think it is worth considering Belgium too if one is looking for contemporary manufacture. (I won't bore you all with the Saint Louis / Vonêche / Baccarat / Val St Lambert entwined history - and d'Artigues, Kemlin and Lelièvre - and unless someone demands it.)
Another possibility to bear in mind is that the sulphide medallion and the paperweight could have been made many years apart. I recall that the sulphide medallions were often made elsewhere than the glassworks, and so could have been available and used perhaps as a trial piece prior to a more up-to-date design of paperweight being made.
Also, given the rarity of items like this, I wonder whether it was a one-off, made to order item, rather than a production piece?
Alan