Glad to help you out, Tim.
First, for postwar Lionel servicing, the one stop site for service manuals is Oplsens.http://pictures.olsenstoy.com/searchcd1.htm. Exploded views and parts listings for locomotives, operating cars, transformers, switch tracks and accessories can be found there. Part numbers for most parts are on the diagrams. Olsens also sells parts, as well as The Train Tender http://www.ttender.com/partslist.html and Brasseurshttp://www.traindoctor.com/service/lionel/0to120.php. There are other parts dealers, but these are the most referenced.

Larry