Looks like a nice glass, sturdy looking. I wonder how the red was cut away? I suppose the likely candidates are acid or sand blasting but is it possibly ground by wheel?
Some of the convex curves look to be made up from several linear cuts (such as from the side of a wheel) rather than a flowing edge from a nicely curved mask if using acid. For example, if you zoom in on the last photo, see around the head of what looks like a bird or angel.
Also, when you look at the ends of the narrow cuts, there looks to be a shallow chamfer, but the edges of the same cuts look sharp. This looks like a cut from a narrow wheel. You can see this in the narrow cuts each side of the bird or angel’s tail.
Presumably if it was ground it would likely be older and higher end.