An identically formed weight is shown in the Trade Catalogue for Zibo Zhaohai Light Industrial Products Co. Ltd. for year 2000. It was listed as ref ZH658 (larger version) and ZH659 (smaller version) and was sold with a wooden stand having three feet and pierced decoration.
A few years ago I notified an American eBayer about a another example of this weight, also sold with a Murano label. The seller told me that they received the item via a person in Germany.
Note that the edges of the white inner layer are very ragged. I believe this shows that the white was not applied as an overlay cup (or equivalent) but was powdered glass picked up off the marver (or some similar method) which after cutting does not produce a fine edge.
Personally, I think these are Chinese products that have had a generic Murano label added at a later time. Or does anyone know that they were really made in Murano - and then offered through Chinese outlets??