I have a paperweight that is like your two. I also have not figured out who made it. My paperweight looks superficially like Fratelli Toso in having the canes set into a bed of aventurine, but the base is very different. The base of my paperweight has edges that look melted, instead of the crisp ground, polished base that is typical for Fratelli Toso. The aventurine also looks disorganized. I wondered if someone might have tried to polish the bottom of my paperweight using too high an RPM setting and caused some melting. It is difficult to tell without knowing the history. What are the bases of your paperweights like?
The labels are generic, so don't give much information beyond that they were made in Murano. The canes are carefully placed, so they are good paperweights, especially if the base on yours does not look like mine.
Sorry I could not be more help,