According to Andy McConnell's 'Decanter' book, Simon Gate and Edward Hald produced bottles with cork stoppers - some with rings like this one - during the first half of the C20 which includes the period this one appears to have been made.
On that basis, there is no obvious reason to imagine that yours is a replacement stopper, but perhaps not possible to be absolutely certain - but it does look the part, and likely to be correct.
Some big names, both in Scandinavia and northern Europe, were creating these engraved bottles, with what I suppose would be called Modernist decoration............ I bet there will be a few people here envious of what you have. ..... very nice bottle, and a good price.
Would imagine you must obviously realize that the designer was Simon Gate - the rather over-done anatomical features are typical of his nudes - I see there is another similar ish bottle on the internet at the moment for which the seller is quoting a date of 1928. The other numerals appear to be the code for this particular design. According to the books, earlier glass is signed Gate, with later pieces showing Simon Gate - apparently he joined Orrefors around 1916.