Hi again,
Yes, the characters looked very Japanese to me, also, but the form, thickness of the glass and that fretwork design reminded me so much of Chinese glass. Perhaps nineteenth century, but if you say there is minimal wear to the base that does not bode well for the age of the piece.
re: "The chop (cartouche) is the key to this piece but who the hell would know this stuff?"
Well, that's been my problem over the years whenever I have had to deal with an Asian piece of pottery, glass etc. Finding someone to read the inscriptions can be very difficult unless you have access to a native speaking person of the language involved or a scholar in that field. I wish I could be more helpful for you and your friend but I noticed your query wasn't getting any responses and thought I would throw the wrench in that the piece might be Chinese instead. Just didn't want you to overlook that as a possibility and go down a blind alley investigating the piece if that suggestion could help.
good luck with your search,
deank