I am not the best to answer this, but I would think no. Can you ball
the wire first, then put it through the copper enamel, and then
finish the brass on top?
I do a bit of enamel, and I am always trying to to do things that
"can't be done" if I understand the design, this is what I would do.
I would also put the ball wire into a piece of board or metal with a
small hole, and hammer the ball flat, so you have made your own nail
to use on the cuff. If you have a vice, put the vice at the
narrowest that will support the board, and the remaining wire through
the opening. File the edges of the nail head so it will be smooth
against the cuff. It will hold better that way. If you don't have a
vice, find something in the house that has the same feature. the
first thing coming to mind is the opening in a table for an extra