Thanks Sue, I think you're right. I've just had a quick look and found a labelled vase in a very similar colour combination on ebay; item 360313845749
Just to be sure I've e-mailed Alum Bay so I'll see if they get back to me...
is the base very slight curved inwards all round towards the pontil mark? sort of dougnutty?
Yes, the base curves in towards the pontil mark, then there's the blob of melted glass. It's interesting as the other Alum Bay vases I've owned had always had rough, snapped-off pontil marks.