welcome from me too, and sorry, I can't help either. This is a large and attractive piece - larger than might be expected perhaps in this guise from the 'nouveau' period, but I'm curious about the crimping of the rim. The Victorians were very clever and quite meticulous about their crimping in the sense that such features were mostly very symmetrical, but on this piece the crimping appears to be less than evenly spaced and uniform - of course I could be seeing this in the wrong way. Is the crimping symmetrical?
The early nouveau period was awash with multi-coloured glass with decoration in the form of pond life and reptiles, often in the form of grotesques, and made both sides of the pond plus the continent of course (Bohemia), so we might struggle to nail down its origin. Iridescence, inclusions of silver and gold foil were also commonplace, plus surface gilding.
Are you able to tell us how this was described when you bought the piece.
