Having looked through the recent publication from Patricia Coccoris, this one seems to be an unusual shape. In the book there is a reproduction of a page from a French catalogue from 1885, showing an example which is about the nearest I can get to the shape of mine - page 114 - No. 1022. Apparently, the catalogue seems to have considered that several shapes illustrated, including this one, to have been 'English Models' (Formes anglaises).
I haven't a clue as to whether this is correct or not - the colour seems to have been quite universal, and the only thing I can say about this one is that the snapped pontil mark plus heavy wear makes me consider a date of somewhere in the third quarter of the C19 - or perhaps even earlier
Was this unusually shallow pan top a feature of some particular manufacturer, possibly??
So if anyone would like to add to my limited knowledge, I'd be interested to hear if people think it is of British origin, or not, and possible date of manufacture. thanks for looking
Ref. 'The Curious History of the Bulb Vase' - Patricia Coccoris - 2012 (a must if you have the remotest interest in glass)