hello Nicky - doubt that you'll ever find a maker. As you know, some C20 cut glass carries a backstamp, but generally pieces dating prior to about 1920 ish don't, and unless you can find a particular design in a catalogue then attribution is a complete non-starter.
The foot appears smooth which suggests Continental, but not a reliable indication of origin, and it looks thick and clumsy, lacking any cut decoration or base star. In removing the pontil scar I'd suggest the base was simply ground/polished flat for economic reasons.
What is the extent of wear on the underside of the foot? - and looking at the shape of the top rim, am wondering if you're missing a lid of sorts.
The decoration is fairly common for cut glass - relief diamonds - although they aren't in relief literally - it's just an appearance from the style of cutting, and fan splits. Is the cutting sharp, or does it feel smooth, which might indicate a more recent manufacture. If I had to suggest an age then possibly first third of C20 - if it was C19 then I would have expected a better quality foot and considerable wear, plus some damage to the points of the diamonds.
The star like mark might possibly be a result of where the foot or stem would have been attached to the bowl part - but I'm really not sure on that.
Such pieces are often a disappointment when it comes to provenance, but regret we have to live with that. Hope you like cut glass, and it is an attractive piece - let's hope someone can give you a better idea of its history.
