from your ebay listing.... "I haven't found anything quite like it in my research, which was fairly extensive including glass message boards as a last resort. No one seems to know."
What I do know beyond a shadow of a doubt is that it is neither Loetz, Kralik, nor old..... and I would be quite surprised if it was even Czech....
The finish quality of the rim and the underside suggest contemporary mass produced glass and not a better maker.
I might suggest in the future if you are going to use a message board such as this for ID of a piece you want to sell, you post it more than 4 days prior to starting your listing.... some ID's can take months or longer...