You could always make a new fiber wash or you could order one from the TrainTender (see picture).
When you reassemble the light, put the spring on the wire first, then thread the wire through the lamp socket, then through the searchlight housing. The spring between the washer and the socket keeps the bulb tight in the socket.
Before you order, check to see if you need anything else, since the postage is more than that lamp lead assembly.
