I am trying to find a replacement shade for a pair of these 70s era lamps but not sure exactly how to identify this style for search purposes. It's maybe a 7" width at the top, about 18" width at bottom. 12-13" height. Is it called an "Empire" or "flared" or a "bell" ? I've seen varying descriptions - Not so much looking for the "knife-pleated" style- a hard cover would be fine - just hard to locate any without knowing how to define the form and design. Any advice much appreciated, as well as where to buy an inexpensive, close match: ) Thanks!