Sorry, the jury is still out on this piece. I haven't got a clue, other than to say that it is a quality piece.
I wish I could give you more information. If I find out more I will let you know. I cannot find anything like it on the internet and I know if someone doesn't reply to a post here, that they don't know or the right person hasn't chanced along. I am patient and it is a keeper, but so far, all of my glass is :lol: :lol: