I suppose there's a difference physically between a flared rim and an everted rim ………… suspect flared is easier on the lips than the latter, but whatever, looking at my 'bristol green wines none appear to have a rim like this one, so assume this rim feature is unusual. Bickerton is very mean on the number of coloured wines that he shows - none has an everted rim and for some reason he doesn't show a deep green example, though obviously they did exist - perhaps he was unable to find a genuine C18 example - and his period stops c. 1830 anyway.
This one is a tad chunky, so could well have been made with the word goblet in mind rather than a standard wine glass, but I could be very wrong, and doubt that it matters whether we say wine or goblet for this glass. Does this one have a good lead-glass ring?
Obviously, no way of telling where this was made - apparently the Continentals were keen on drinking white wine out of their dark green glasses, and maybe this was a universal habit in the C19 - unsure why that should have been - perhaps they were using the colour to hide the sediment?
No idea really as to age - Bristol blue/green have been popular colours for 200 years and remained so well into the C20 - have a look at page 406 in Hajdamach's 'British Glass 1800 - 1914', plus read his text on the same page ………. reference the reproductions from the likes of Hill Ouston.
It really is a minefield trying to date these things and no way ever of knowing the maker, obviously. Wide feet are supposed to indicate greater age, and feet that are narrower than the bowl rim are said to be not so old, but nice glass Keith, and if pushed I'd go for c. 1860 to 1930, but that really is a non-academic guess
