you're not getting off that lightly

........................ sea green ceased in 1959, apparently, and the style of twist on your stems has a more recent appearance - am sure I've seen this sort of thickish twist on quite recent pieces - glasses I've seen in charity shops I'm sure.
Do you have either of the W/Fs. books? I have the smaller one edited by Leslie Jackson, which is rather limited in it's coverage of shapes etc.
Not that I would pretend to be well up on W/Fs. - in fact I'm well down - but imho it's perhaps unreliable to create an attribution based on colour alone.
No reason why I should have noticed this previously - since my interest in W/Fs fell by the wayside a long way back, but there does appear to be an error in Leslie Jackson's book - in the glossary - which concerns these colours.
Under the heading of 'sea green' in Jackson's glossary (p. 151), the lady comments that this colour was used on lead glass from 1893 until it was replaced in 1959 by 'arctic green'. Jackson's glossary omits any entry for 'arctic green', which does look to point to the fact this was a typo and what was meant was 'ocean green' - for which there is an entry (p. 149) .............. "a cool pale green colour introduced in 1959 to replace sea green etc. etc. ......... remained in production until 1966".