Unknown green slag glass lamp

This hanging green slag glass lamp was given to me and my family. It has no wiring or chain coming out of it, so we don't know if it still works ( the picture above with it lit up is with a flashlight held under the lamp). The original light bulb is also gone, but it does have a milk glass cover. The outside has a thin floral metal filigree that's been painted a creamy white/green color (is that the original color?). The entire shade is about 15" tall and 13" wide at the base. There are no markings that we've seen. We've managed to find three other lamps online that are a bit similar in style but not really the same. If anyone has any information on the age, manufacturer, pricing, or history of this lamp we would be very appreciative!