Hi, welcome aboard. This style of cutting is not my area. All I can say is that there seem to be some similarities to what Czech GMB member Jindrich has described as, "Typical Bohemian cut had been invented in 1929 by Mr. Prostrednik and is known as pattern PK 500.
Since that time up to now is reproduced and used with slight modifications. "
If you research Podebrady, the factory that first produced this style of cut and made it popular, in conjunction with this PK 500, you may find some interesting results.
http://www.cs-sklo.cz/ceskoslovenskesklo/ Jindra's site may have Podebrady catalogues.
good luck researching. It looks like an excellent piece but whether it is a special piece from 1940 or 1990 I do not know enough to say. Sadly, I do not think Podebrady is still going. Some excellent cutters migrated to the US in the 20's and 30's and continued trading. A signature, on a big piece like this ought to be traceable as signing this kind of cut glass at all is highly unusual in my experience and indicates an unusual piece of glass. I don't think I have seen any signed examples actually, most are not. (If, it is indeed Czech which is not certain but seems possible, at least
to me). If another GMB member prefers another origin that may be worth looking into, until then Podebrady researches will at least give you an area to start with, good luck, be warned, glass research is addictive!
Robert (bOBA)