My digging was a bit easier. I cannot find anything that looks like your glass in Jackson, although a lot of the photos are B&W and in groups for exhibitions.
In general, as I'm sure you're well aware, Powell tends to have long slim elegant stems and the glass itself is very finely blown.
Your lovely glass just doesn't have that thin-ness or quite the elegance of something that harps more to Art Nouveau, the way Powel does.
There are very few glasses even with bowls the same shape as yours, with cup shaped, rounded bottoms.