I don't see any reason to doubt the antiquity of the alabastron you show. However, I think it might be considered out-of-place in the dialogue being presented in this thread.

I think the online article presents a very good view of core-forming glass artifacts (including beads) as this was practiced in antiquity—with a few provisos.

First, I hope readers will notice that the "core" is the part that is removed from the object once it's completed and cooled. This is why I stress that, in beads, the center or main part of the bead is its BASE, and not its "core." If everyone insists upon calling the base a "core," we'll have to think of a new name for the cores of antiquity. In core-formed beads, the core is the combination of the mandrel or rod and the layer of separating compound around it, that form the perforation. The primary difference between a core-formed vessel and a core-formed bead is that the the channel of a bead goes all the way through—whereas a vessel is formed on the end of the rod, with one end closed-up. And Vessels are more often formed on shaped cores, that are much thicker where the body of the vessel is made.

I note that the makers of their reproduction say they used a preformed rod to apply the decoration. In antiquity, usually, the decoration lines would derive from a hot glob of glass, taken from a crucible, that would be attenuated and trailed onto the base, pressed in, and combed. So, there is a small anachronism here, in the reproduction (that tends to blur the differences between furnace-work and lampwork). Unfortunately, the writers refer to the tooling as "feathering." This is a mistake we face every day with many beads. The terms for the tooling are: "combing," "raking," and "dragging." One pattern that can be created is called a "feather pattern" that results from widely spaced thin trails being alternately combed up and down. However, the pattern of the vessel in question has a wave or zigzag pattern (which is different). I discourage calling this work "feathering"—particularly when the pattern is NOT a feather pattern (!).

I note that in a previous reply you cite where the comment is made that the object is an alabastron of "Molded glass." This is another all-too-frequent mistake. There is no "molding" of these works—though there is MODELING (which is very different) ! Then, in the next citation, a series of vessels is show and named—and most of them are also called "alabastron"—which is correct for some of them but not all of them.

There is so much lack-of-precision on the Net (and in many books).... But the pictorial is instructive—and their results are quite good.

Jamey