Christine's reasons for suggesting modern sound rational and I'd be tempted to agree with the indication of C20, on the basis of those thoughts.
I've had a look in McConnell's 'Decanter book which was given as the primary reference source in the first link from m, and the shape of these things seem to have remained fairly consistent with their twin handled shaft and globe design, rigaree decoration and the use frequently of engraving showing diving birds and windmills. Examples are known with one handle and some without any, and some with stoppers too.
Quoting from Andy McConnell's book (page 405 - 406), when speaking of revival/reproduction styles etc. he writes ...............
""Salviati's most popular reproduction was a thin-walled, twin handled shaft-and-globe encased within a series of pinched vertical ribs, and often crudely engraved. An ancient form, known in Norway as a
Ziratflasker (plate 569; see also plate 220), numerous other makers were soon copying Salviati's reproduction. According to Eastlake in 1868, versions made across Europe 'are now produced at the price of a common decanter' (plate 571).""
McConnell's ref. to his plate 569 shows original and revived examples of
Ziratflasker - 1: an amethyst (although to me it looks like cranberry:))
Venise example, probably Low Countries, c1700; 2: Dark green example crudely engraved with diving birds, Bohemian, 1880s or 1930s; 3: Colourless
Venise example, late 17th century.
In numerical order these pieces shown have - one handle - two handles - without handles, and most of the early examples look to have had a quite substantial 'kick' in the base.
McConnell also includes a reproduction of an illustration from a 1936 H-O. catalogue, for which the original catalogue caption reads:
"8240 - DUTCH SPIRIT BOTTLE WITH STOPPER. - Engraved Vine - Height 11.1/2 in. - 42/- pair (Sterling two pounds and ten pence in decimal)".
The authors own text accompanying this illustration reads:
""Plate 571. Illustration of a 'Dutch' spirit bottle' from Hill-Ouston's 1936 wholesale catalogue. It is decorated with engraved diving bird, similar to those on Plate 569/2""
Finally, McConnell's book reproduces copy of a Punch (C19 British mildly satirical weekly magazine) cartoon showing dinner guests seated at table on which the distinct shape of a
Ziratflasker can be seen. Part of the caption reads "Plate 570. Venetian revival
Ziratflasker were sufficiently recognisable by 1886 to become an easily identified decanter form for a Punch cartoonist."
Shame that Andy McConnell's book isn't more widely available - we can't reproduce the images here of course - so impossible to appreciate the pictures shown in his book from words alone.
Sorry - had to revise some of this wording ............. does the name 'Ziratflasker' have an easily translatable meaning, in English.
Ref. 'The DECANTER An Illustrated History of Glass from 1650. - Andy McConnell - 2004.
Invaluable reference source for anything to do with decanters and much else besides relating to the history of glass - truly a marvellous book. All credit for the above information is to Andy McConnell and his book - none of this information is mine in origin.