It certainly looks like an early Aurene goblet from IoWSG.
Can I ask, is the photo "squished" or is this really the shape? I am assuming it is right, because of the dimensions you give, so I'm going to carry on and say That I suspect this is an early, experimental piece, made before Aurene was fully developed into an official range.
I have a few pieces of early experimental strapped "Aurene", produced using some enamels that the Harris family brought back from Malta, and so have the Mdina teal blue in them, rather than the more cobalt blue used at IoWSG.
You say there are different shades of blue in this?
If there is the Mdina teal, that would indicate use of enamels brought back from Malta.
The very wide shape is not standard at all.
I do think this is IoWSG, and an early, experimental Aurene-style.
I am not able to comment of who might have made it, it's possible it was Michael Harris, but it doesn't scream MH at me. Some of his work doesn't.
I have a feeling that the definition of whether something is gold or blue Aurene, depends on which colour is on top, but I also think that most of us just call all of it Aurene.
(John and I were replying at the same time.