Slag Glass Lamp with Metal Detail on Shade

My grandma received this slag glass lamp as a wedding gift from a relative, and based on what we know about it and the family member who previously owned it, we suspect it to be dated some time pre-World War 2. The shade is separated into 8 flat panels with metal design overlaying some parts of the glass. The base has similar patterns to it, and we are relatively certain the shade and base go together. The lamp is in working condition, and is all original parts. Upon examining, we saw no specific marking indicating manufacturer, even when we lifted to examine underneath.

In addition to the photos showing the entire lamp, I included an image showing the lamp still works, an image of the shade from above, and close ups of the base and the metal detail on the shade.