Anik - my thanks again, and have to say that although I was involved in the item you linked, I had forgotten completely

However, having looked at the base of the linked vase - and now again at my green one, there are quite significant differences. These are.......the clear vase has mould lines which thicken considerably as they go away from their centre - mine do not, they are quite fine and are uniform throughout their length. My lines 'turn the corner' of the base, and come up the side of the vase, albeit for about a centimetre only - the clear lines do not. I could be wrong, but the clear base lines appear to be sunken - the green ones are certainly in relief. The bottom line of the clear 'knobbs' is very near the base, whereas mine are at least 2.5 cms. up.
Of course, the green vase may well still be from the same stable as the clear piece. However, I will keep an open mind just for the moment.