Hi smokerstill.
I have looked all the way though the Whitefriars Glass book, James Powell & Sons Of London. but can not find any ref, to this vase also i noticed the pontil looks a bit rough not polished.
also went though Whitefriars Glass the art of James Powell & Sons by Lesley Jackson. no ref.
You could always post this on
http://www.whitefriars.com and at the same time look though their catalogues
will keep looking and let you know if i find anything,
Steve
PS i see aj you have already posted on WF .com