NB mark, Norah Braden vase?

I have a studio pottery vase with an 'NB' makers mark on the lower rim. The glaze on this vase is quite thick, and so it's difficult to photograph this mark clearly. The N and B have been joined together so that the second vertical line of the N is merged with the vertical line in the letter B. could this potentially be a vase by Norah Braden?

Any help to confirm the authorship of this piece would be greatly appreciated.

the clay looks to be a good match

I don’t think so, unless it’s an unrecorded mark. It’s not one of the ones in the Marks book - her usual NB stamp is in a hexagon rather than a rectangle. And I’m not finding another of hers in this shape or glaze.