I still think it pat. 9355 Nic. I have VERY closely examined mine - I have a Sea Green and a Sapphire Blue. Both of mine have slightly different bases, one more lobed than the other. I think you may be confusing vertical optic ribs with the natural small "folds" in the glass as it tapers to the base. Almost like a crease. If they were true optic ribs, whether vertical or horizontal, they would create some distortions in the glass when viewed from the outside, which they don't seem to be doing on yours, and certainly not on mine. I do think it is a slightly "off" shape of 9355 which is a bit more tumbler shaped....don't forget these were hand blown items and some slight variations may occur....remember the beaked vases we discussed some while ago and the variations in sizes and shapes of those?? Emmi