Stevens and Williams is listed on 36 pages in the index of the 2nd edition of McConnell. Not read all the text but there is a similar shape Stevens and Williams one on page 373, Art Nouveau Decanters. That has fancy organic looking cutting though, green cut to clear, dated c1895. Out of interest, on the same page there is also a 1931-35 Amethyst-over-crystal Cameo Fleur decanter by Webb, also very similar in shape.