NOTES ON THE DECANTER ONLY............
Not for sherry probably, but more likely either a spirit decanter, or possibly one from a set of 2 or 3 of the same which would have formed a 'liquor frame' - similar to a tantalus, but without a facility for locking. It's the straight sides and more narrow body that suggest this use.
Regrettably, provenance/attribution is a none starter - for the last 350 years decanters have been made in limitless profusion - although in the C20 some factories included an acid backstamp showing a trademark etc., for example Baccarat (France) or Stuart (British).
Decoration wise, there is slice cutting on the neck down to the shoulder, plus some wheel engraving in the way of small stars and a decorative band of matt diamonds, with further proper cutting of ovals at the base. Again, a base picture would have been helpful.
The small decorative stars are a feature that go back to the mid C18, but that aside there is nothing else to suggest any real age, so I'd plump for something like 1850 - 1880..........the Victorians were nuts about those small stars and shoved them on almost everything they could get their hands on.......just have a look in the Silber & Fleming volumes (sections on utility glassware etc.)...........more books that for the collector of Victoriana are extremely useful, and which again must surely be available on ebay etc.
Pity you don't have the stopper, although antiques fairs and sometimes up-market boot sales can turn up boxes of mixed stoppers and you might just find a suitable match.
Try looking on the lip (inside and outside) - and the neck.......for a number (the matching No. which indicates quality if nothing else) - might just help with showing if this is Continental or British.