My first thought was an early perthshire, although this pattern doesnt seem to have gone into production.
Just looked in the Perthshire book and on page 8 are a collection of moulds. In the middle, second row down is the mould in question, perhaps a leftover from vasart. I guess this was only used very rarely early on.
With regard to JD, the swirl is rather his type isnt it? (cant find a reference at the moment). Could he have experimented with this swirl while at Perthshire, because the canes are not like his personal early ones I believe.
Another interesting thing is the swirl does not go to the bottom of the weight. The base seems to have been a fire polished, then minimaly ground out. The diameter is 3 inches. Roger.