I didn't see the pontil mark was ground, although I was looking for it.
I thought it was clear and kind of a stepped bottom shape.
If I'd seen the mark was ground, (and I can see now there is a sliver unground in it), I'd have said Chinese, without any doubt.
You are developing a good collection of Chinese glass to study and get a feel for, Roobarb. You really need to get out and about (I know that's frustratingly impossible right now) and get your mitts on lots of different kinds of glass, to get a feel for it.
You need to come along to the big fairs and meet us all and we can happily talk and study the glass with examples of it in our hands until the cows come home, and we can take the glass we've chosen home with us too.
(I'm really missing getting to a fair and meeting up with everybody. It's the highlight of my year.

)