Apologies Auliya,
I did not read your post properly, I thought you were just posting very hopefully expecting an instant reply (it sometimes happens!) Rereading more carefully, it appears you have tried pretty hard to look into the origin of this piece. I really am surprised that such a striking, distinctive design is without attribution. Knowing it is on the pressglas website is some help, but not having an attribution there also tells you it must be a piece struggling to find an attribution. i hope you get a result..... I do not have much advice to give sadly.... colour and base shape are evidently not directing where it is from at all and I would ask where you bought it but with pressed glass, country of origin is almost no indication of manufacture .... Only a labelled example can help and maybe recording more colours, that can be a clue.......
best of luck,
Robert (bOBA)