Thanks all. Although this is not my vase, when it was originally listed it sold easily enough and was shipped to the seller. My friend (a newish eBayer) then gave feedback... and was then held to ransom by the buyer "not WF, dip in the rim, 1/8" too short (yes, honestly!) blah-di-blah"). So the vase was returned for a refund and I gave my (rather weak) appraisal that it could be Ingridglas.
But this has restored my faith. I will send it back to my friend who can now list without fear of contradiction (and without leaving feedback first!)