Keith — I found your original query
here, and noticed that Ivo had identified it as Service George Sand by Cristallerie de Portieux, Portieux, France. I've had a browse around mainly French websites, looking at examples of this range.
My conclusion is that there are too many similarities between Service George Sand by Cristallerie de Portieux and my vase (and yours) for them to be likely to be anything else. Note the same optic rib mould and the ground and polished rim, for example. I've not found such applied decoration on examples on French websites, but it seems to me likely that such pieces were made for export, and may not be well known in France.
As for date, it's difficult. I'm with "early C20", going on the style and base wear.
Finally, Keith, I'm always very wary of old unsupported Boulton & Mills attributions, and tend to regard them as a pompous way of saying little more than "Don't know", or, to be generous, "possibly Stourbridge".
Grateful thanks, Keith and Ivo.
Bernard C.
