Hi Deb,
another thought…you could solder the two domed washers together…and then create a tube/ sleeve to “close” the hole…
…slip tube thru the hole, then stretch the openings to get a tight fit at the edges, by using a dapping punch in a vise for one end, and another dapping punch on the other end, and then hammer that punch to simultaneously stretch both opening very slightly…
could also dap down the washer hole a bit first, then fit the tube sleeve…
julie
similar to a solution given for a pendant repair…