Carlo, John & Cathy â€” Over the last year I've seen three similar vases, all slightly different shapes, that looked like Webb, S&W/RB or Whitefriars certainties until I picked them up. They were too light and the rims were wrong. Now, I could be being overcautious, but I am starting to think that the examples I saw might be recent.
If you can get it to a large general antiques fair or a reputable auction house, Carlo, you should be able to find someone who will help.
Once you know it's OK, then you need to establish which of the three made it â€” as John says, not always easy!