Pardeep Sodera used to work in Hungerford near Newbury around 2000.
I don't know where he is now or if he is still making these weights, but
I have one dated 2004.
Incidently, they are not carved as you say, but sandblasted. A resist such
as PVA glue is painted onto the iridised blank in the shape of the design (dragonfly)
Then when the resist is dry the weight is sandblasted - this removes about
1/2 mm of glass from everywhere other than the area covered in the resist.
The resist is then cleaned off leaving the iridised design in relief