Thanks for the response.
It is, as far as I can tell, a known Verlys design. There is this one (the Bees), another described as Butterflies and another described as Moths.
As you say, it is clearly etched - but in all my searches I can only find either embossed Verlys marks or those engraved/scratched in a signature style looking mark - nothing like this, as you say stencil like etched version. To me it is reminiscent of writing done with a cut out pro forma. (Those plastic rulers with the alphabet and other symbols cut out for you to make neat headings etc.) It isn't really that important if it's genuine or not, as we like the vase, but I'm a little intrigued - it may give some clue as to age perhaps.