This is one of Willie Manson's and I think it is from the start of his own venture William Manson Paperweights, founded in 1979, after he left Caithness earlier that year.
It's called Butterfly and Flower. Some versions were faceted, as were the same design (with the same name) made by Willie at Caithness in 1978 and 1979 (CT-107 and CT-140).
I have one exactly the same, with the same colours and canes and also not faceted. However, mine has a WM cane in the base and the 79 cane in the flower, below the central bubble.
That style of lampwork butterfly is indicative of Willie's work.