Hi,
The 'Venetian Ripple' moulded technique was used by Stevens & Williams/Royal Brierley on their own production ware (see the example placed at the beginning of the thread0 as well as by outside designers. Both Keith Murray and Constance Spry used this moulding; as far as we know all examples by Spry use it, whereas only a very few by Murray.
I have a blue example exactly the same as yours Keith, I also have a Rainbow ware flared vase with that moulded surface, and another barrel form one with an engraved flower having sinuous tendrils, that is marked 'Royal Brierley'.
Nigel