Mike kindly sent me a photo from the Boston & Sandwich book showing the both the Sawtooth and 'Ananas' vases, the text was interesting too stating that some of the Sawtooth vases had no hole between the centre and the trumpet as they could be "plugged with an excess of glass from the trumpet". I have not seen anything like that with the two Ananas vases, how open is yours Mike?
Quite what relevance this may have is moot but I think that on the Ananas vases the upper and lower rows of bobbles are applied rather than moulded like the rest, some have irregular shape and positioning. They might help disguise the join a bit too, from photos the sawtooth pattern looks entirely moulded, it would be nice to have one to compare in the flesh!