Thanks for the suggestions.
My initial reaction was Whitefriars, too, cos the feel is right, but I've never seen a WF vase or bowl with 6 base lobes, only 5 - the 1950s molar vases, the lobed vases from 1978-80, etc.
Presumably the pieces are blown into a mould to create the lobes before the item is finished (I've had the odd go at blowing glass, and a little knowledge is a dangerous thing...)
so if this is WF I'd expect there to be other WF pieces with 6 lobes. Do you know of any?
The blue does match the WF 1980 sky blue pretty well, so this could date from around that time.
Why do you think S&W, Max? I'm fairly iggerant of their products, and am only acquainted with the earlier cameo stuff etc.
I'll post this on the WF site, too, and see if Patrick rises to the bait.