Welcome to the board, Leigh!
Concerning your power cord issue, the original power cord plugs were molded in one piece. If your plug has the internal wiring exposed, it sounds like the plug was replaced in the past. You can either cut a thin piece of cardboard to cover up the wires, or just replace the plug. You do not need a 3 prong plug or wiring, as it is not necessary, and transformers are safe without them.

Larry