The shape reminded me of a rainbow shape but on closer inspection it might be a little too flared. And the shape of the foot in profile in your pic also looks too flared by comparison to 'rainbow'. Although wracking my brains that profile of foot does remind me of a pale blue crackly vase I have that is the same as those urn shaped crackle vases often muted as S& W but with no definite id iirc.
On the other hand ... the bubbles and the way they are spread remind me of those in my cloudy vase (which is cloudy
and bubbly and is S&W), the foot reminded me of this one from Keith, which is possibly S&W as it seems to match your green version on that thread, and which is the same shape as my S&W pink cloudy with bubbles.
http://www.glassmessages.com/index.php/topic,41369.msg288681.html#msg288681And the pontil mark is right for Stevens and Williams. So I guess my mind just automatically saw Stevens and Williams

Is it quite heavy?
I'll have a look in the book at the two you've mentioned.
btw I guess you've seen this one which was sold as John Walsh Walsh? presumably Pompeian as it seems to match the picture here (sorry I've not had time to double check books for it)
http://www.antiques-atlas.com/antique/john_walsh_walsh_art_deco_bubble_vase/as296a176but your vase looks slimmer towards the foot and not quite the same shape and thicker glass
http://www.glass.co.nz/johnwalshwalsh.htmPaul, also see this thread - the purple in this one does look different to that of your vase. Yours looks a bit darker (reminds me of Richardson purple

)