Interesting. Bryn, have you seen the 'tulip' (for want of a better name) vase in the initial posting, or the 'rocket' vase (ditto) with an acid etched mark? I never have personally.
Not saying you're wrong, just trying to fill my gaps.
The only place I've seen the 'rocket' vase attributed to Okkolin is in Millers guides, so I've always taken it with a pinch of salt. Having said that, I did say the same for the 'tulip' vase, but I do trust Andy McConnell, who spent a long time visiting the factories if he says that one is definitely by Okkolin. I'll ask him about the 'rocket' when next I see/speak to him.
Edited to add: The 'rocket' shape that Nic and I are thinking of isn't on Page 29 of Fire & Sea, so we're barking up the wrong tree accidentally.