M, I am not convinced that the vase in the link to the Corning Museum item would be the source of a misattribution to Webb! And I am also not convinced that all items with the generic "Moroccan" (or whatever) decoration style which are suggested as "Webb" are misattributed.
In Post 16 above (please see for full context), Cathy said:
Manley references a Webb sketch book of 1879 but I have no idea whether the sketch really shows the same decor, which is described as alabaster-cored, with square top and enameled.
For completeness, and as food for thought as to whether Manley may have been the source for the Webb attribution, the following is the full text from page 75, Item 185 in Manley's
Decorative Victorian Glass, published 1981:
A vase for identification, most deceptive. The first impression is obviously French, but Thomas Webb's records (sketch-book of 1879) describe them as alabaster-cored, with square top and enamelled, and it is only when a number are placed alongside each other that this is realized, all differ in some way. 19.7 cm (7 3/4 inch) high.
There was also an earlier publication,
Collectible Glass, Book 4, British Glass, copyright 1968, which was based on Cyril Manley's collection. That book covered many of the same items as shown in the later book but it did not include the "Item 185" from the latter. I mention this as it
may be an indication that Manley secured the "Item 185" vase much closer to the preparation date of his later book. But it could also mean that it was simply not selected for the earlier book!
And on the subject of dates, I wonder whether the possible Turkish items are all very modern "copies" of the style and decoration. To my eyes, the colours
and condition of the decoration seem much brighter than the few examples (Webb, Harrach or "other Bohemian") I have seen in books or illustrated elsewhere.