I'm fairly certain it's not Webb. I think you need give it more time on WF.com and maybe point people towards the 1940 catalogue. 9147 is quite a scarce pattern and many people won't be familiar with it. It would also be helpful if a moderator could change the title here to attract the Whitefriars collectors.
While your vase seems to taper in a little more towards the base than the catalogue drawing, I can see nothing that definitely rules out Whitefriars (the difference could be just down to individual variation - also the illustrated examples I've found were all in the larger size, not this 6 inch version). The 6 sided pattern, the style of foot and the dimensions all match the smallest size 9147 vase. Likewise 'Flint' (clear colourless) was a catalogued colour for this range. The time period is roughly correct; 9147 appears in the 1940 catalogue and the 'Celery' mark on yours dates it from 1942 onwards. Therefore, on balance, I think it is likely to be Whitefriars and is quite an interesting find.