Ok, now I have another look at the photo of the top of the stopper (at a 200% enlargement) I can see that the leaf garland and central leaf motif do seem to match the leaf swags around central leaf motif on the body. So on that basis I'd agree they were made for each other.
It was just that at first sight, I thought the stopper would have had a more rounded form to follow the lines of the shoulder of the body. And also, the stopper seemed to me to be leaning a bit, suggesting a not too good fit.