General info:
Examples of signed "Tel-El-Armarna" items can be viewed at:
Sotheby's New York 2104 sale, lots 1 - 7 (use "navigation arrows to scroll through from No. 1 ). All are signed ("engraved").
Note that "Tel-El-Armarna" referes only to the banded decoration around the neck or base of various "Favrile" items.
Also note the comments in the Catalogue Note for Lot 1, where the term "Tel-El-Armarna" is discussed as being a currently accepted alternative for "Egyptian Collar" but which should perhaps be known as "Byzantine". The reason given is that "Tel-El-Armarna" was apparently intended for a shade of blue, rather than a form of decoration.
Perhaps only Vases with "Tel-El-Armarna" decoration were signed and the Egg-shaped items were not?
Edited to correct my misspelling of "Armarna".