Antique White Bisque Lamp With Grape Motiff Identification

I inherited two of these from my parents, who I think purchased them in the late 50's. I've been able to find other examples, described as White Bisque, Porcelain, Ceramic, Art Pottery, Blanc De Chine, Art Nouveau, and Cottage Décor, but no specifics as to the maker, date made, or what the actual description is. I can't see any marks, other than what looks like an inspection sticker. It measures a little over three feet from base to shade support. Any help would be greatly appreciated in. Here are a few pictures:

 

Thanks for the reply. I did check the UL site, and didn't find anything.

 

I'm not positive, but I think those blue labels were used in the 50s & 60s.
I can't see the picture of the plug well, but if the two prongs are the same size, it is 1960s and before. the wiring looks original.

 

This is one of the listings I found that had a slew of different descriptions, but no maker or date. Perhaps this lamp had different variations, but the lamp shade for mine looks completely different than the one in the picture.

Thanks for the response. I have confidence in Antiquers. The members here have never let me down.

 

Lamp shades are often replaced for one reason or another.

I see these are routinely described as being decorated with grapes. I don't know what they are, but neither the shape of the leaves nor the shape of the cluster of fruits/berries is right. Insufficiently botryoidal.

 

They are stylized ...no ?
Do they have to mimic a bunch of grapes to the letter ?