That's lovely.
I would have thought maybe Bohemian as a possible as well? or is there something about it that is definitely Richardson/Webb?
perhaps Riedel or ....sorry wracking brains here -
maybe Reich ? (I'm not sure if I've remembered that one correctly - but I came across a huge catalogue of lampshades and I thought it was them).
I'll have a quick look to double check that but I recall they have a huge online catalogue and I found one of my lampshades on there.
edit - No,not Reich but Schreiber and Neffen

It does look very similar to a Riedel shape lampshade I've seen and they did do a green on clear I think ( I have a vase that I believe is Riedel and is that same metally looking green on clear).
However... I don't have the Riedel book and whilst I am 99.9% certain mine is Riedel, I have never had it confirmed fully with a cat picture.
And I have no idea if they did that 'hammered' background but it has piqued my interest with regard to another thread!
m