Unusual Antique English Art Glass Paperweight Real Plants Half Dome

Rough Dimensions: 4” diameter & 2” tall
Makers Mark: unsigned 
Condition: Good, minor surface marks and wear to the base rim. The plants are faded. Please see photos and let us know if you need any additional assistance. 
An unusual piece featuring a spray of real leaves, grass and flowers and a cloth butterfly encased in a shallow cavity and sealed with a transparent green compound.