Christine, I looked at Fenton Fine Rib but it's not the same as mine. The vertical ribs are there - just not too clear in the picture.
Glen, thank you as always, I hoped you'd confirm it for me.
It really is a lovely vase - even filthy dirty and on a table buried under a load of clutter it looked promising, but washed and polished it is, as you say, stunning. How it survived intact under all the clutter is a mystery for sure! It's now safe in its new home (or its new home until my mother sees it and claims it for her collection!