JP, do you really think there is any possibility this could be a one off Whitefriars piece? I thought I'd better clarify as I wasn't sure I'd followed your last post.
The way it is constructed as far as I can see is that the interior layer is plain, the bubbles and the black splash and spots are then in the middle layer, then it has a further plain layer over the top - at the neck you can just feel the patch of bubbles on the outside where the external cased layer has been pulled thin and is less thick than the body of the vase. The neck is drawn up and is thinner than the body of the vase but then has been folded at the rim inside to create a thicker rim. The trails seem to have been pinched out of the body rather than stuck on if that makes sense.
Sue, I've been trying to take photos of my crackle vase to show how that has been made, in answer to your question about how the one I linked to has been made. I think, if mine is the same, it is crackled on the inside layer, then the middle layer has the 'painted splashes' applied to it, then the whole is cased in a thick layer of glass. I've attached a couple of photos of my blue crackle with paint effects, to show this effect ( I hope - although photographing it was a nightmare). You can feel the crackle on the inside of my blue vase.
m