I would like to see photos of a) the base finish (full view) and b) a full profile view (not angled).
Alan's comments are interesting and highlight a possible confusion with some of the "ysart-like" items that have been made.
However, I believe this weight is very likely an early Paul Ysart item. His lampwork butterflies [as opposed to those with wings formed entirely from millefiori canes] usually had small dots to the outer edges of the upper wings in addition to the larger dot on each wing. But on occasion there are no small outer dots. My own examples (
shown here) do not include the type without the outer dots. But there is a good example in Colin Mahoney's book,
Masterworks: The Paperweights of Paul Ysart, page 88 lower left, which certainly shows the garland canes as "floating" implying that the butterfly does the same.
As well as the example in Colin's book, this particular weight has garland canes which are known in other Paul Ysart work. But to be more sure about this one, UV and Specific Gravity tests would be useful.