These have always interested me, the shape, finish, pontil marks etc are very similar to early Murano weights,
yet the colors look more like French or US scrambles.
Had it not been for the aventurine and pontil marks I would have gone for French or NEGC,
but with those two features that doesn't sit right.
In the book Paperweights, by Sibylle Jargstorf, there is a weight on page 50 that has these kinds of canes,
she writes that these kinds of simple twists were very frequent in the 18th C and again on 1870.
Francini was much earlier and his canes are frequently present in Bigaglia weights.
There is a fantastic Bigaglia weight on eBay at the moment, far faaaaar out of my range tho.