although I think it's quite likely to be Nazeing, I've learned to be a little cautious with these swirled bubbled pieces. There are a lot of rust coloured particles/spots in the glass, and it seems to be about the right sort of green as one of my other Nazeing vases, and looking in the book, this factory did offer some rather large platter shaped items. Diameter is about 15.5"/395mm. In the bottom of the bowl area the colour looks more flake shaped, and the centre has quite a humped kick. A fair amount of wear scratches everywhere except the top of the flange/rim.
Not a very practical thing - footprint to usefulness ratio is a bit low and you'd need a rather large spare sideboard.
Grateful for anyone's thoughts, and thanks for looking.