My mysterious paperweight!

Another interesting piece of art glasswork.
It would be really great to know more about it. I have spoken to a handful of experts, all of whom agree this is an old and unusual paperweight, but are of mixed opinions as to where it could have been made. I came across it on a market stall in the north of Spain, where it sat hidden among many other antique household items, from what looked to be a rather grand old Spanish Masia's (farmhouse) contents.

After stumbling across this marvellous site, I thought I would upload this wonderful piece of artwork to pick your brains. If there is anyone out there with any information about antique paperweights, then please do get in touch, I would love to hear from you and add to my knowledge (albeit rather limited) of this stunning piece. It is possible that this paperweight was made slightly before or during the classic period and I would love to find out for sure.

Many thanks.