20th century - sorry! 1900s.
No links, sorry, but glass a century older is quite different. There are a lot of these sorts of painted, mould blown vases around, so many that we (currently) have no clue about makers.
I think Uranium was first used in glass until the 1850s-ish, invented in Germany, two colours Annageld (gold) and Annagrun (green) were made, named after the gentlman's lady wife.

It's hard to tell much from the pic of the mark on the base. Sometimes marks can look better on piece if taken at an angle across them, so that the ambient light picks them out from the background.
Do you think it is a deliberate mark, or just something that might have got there by accident?
(I don't know about you, but I can't tell what I'm photographing half the time - I can't focus on what I'm looking at and the camera screen at the same time, I don't have glasses that will allow both.
It was much easier with old cameras when you had to peer through a tiny eyehole, you could see a big image there.)