And I am currently looking at a bowl on the site that has the encased foil with amber casing in this instance,with applied fish or lizards (one at either end) and it has a lozenge for Webb. I would say that it has that odd striped appearance as you describe on your vase Kev and in a similar way to that vase item 93 in Manley.
I am going to stick my neck out again and insist that we look at Webb

and that Manley might have been incorrect in his supposition that it was Stevens and Williams

I'm also going to say that he was definitely wrong about what he says re item no 64, a foil encased bowl with applied lizards which he describes as crystal over pale amethyst (looks like dark amethyst to me) 'with silver flecks (aventurine)', which again looks like silver leaf or foil to me or mica but not aventurine - (ref: Antique Stourbridge Glass .co.uk site under Thomas Webb). And that it's not designed by Frederick Carder as Manley implies.
Also,I think the pieces with splotches over foil are a 'decor range' and the pieces which have a perceived striped effect as in Kev's vase and a fish or applied lizard bowl I've seen on the Hier site (a Thomas Webb piece) are a different 'range'.
Also one more observation - the bowl Greg shows looks quite refined in it's making. The links he gives to the Fieldings site to similar decor items ... well those items look 'clunky' to me. It's odd. I think they look like the same decor, but they look like less refined designs/making than the bowl Greg shows don't they? Almost as though they come from a different period or are meant to represent designs from a different time, whereas Greg's bowl looks as though it belongs in the 1880s/1890s when those triangular bowl with or without applied lizards appear to have been the rage - or is it just me?
m