He made use of cut-outs and wire attached with balls of sterling. Two of the balls on this pin are soldered together, I'm sure done when this was made (see bottom of first pic, second and third wire). A deep patina that is desirable to many, but could be polished if so desired.
Miraglia coated his sterling pieces but is notably absent on the front and is evident on the reverse side of this pin. Working pin and locking mechanism. In excellent condition, but check pics as they are part of the description.