SF & Co Royal Delft Vase S Fielding

I got this from a charity shop some time ago and have been researching it on and off ever since. I have seen vases with similar shapes from SF & Co, from the 'Royal' range, but none called Royal Delft. Does this mean it's very rare? Would appreciate your expertise! The shop label said it was Art Nouveau.

Vase collecting is a hobby that has been growing on me over the years, without me really noticing. I live in a flat so am now having to alternate them as they cannot all be exposed at the same time... It's so impractical to spend money on things that could break and are bulky but they are so beautiful. This one was cheap, thankfully.

Thanks, everyone!