See the illustration on Roberts page 82. The cluster containing the clasp is on the right, just below the tiara. Notice how the swag between the next cluster and the swag on the top of the other side are approximately the same size as the other swags. Compare that to the much longer swags on page 85 now flanking the clasp. This is how the necklace was lengthened without adding any clusters.
on November 19, 2012, 10:42 pm, in reply to "