Mike,
Click on most any of our Sponsors that carry Lionel, call them using their direct store number, I started a thread long ago on this very subject, you can reference the thread using FT Lantern, I was lucky enough to purchase a couple I needed and one of the OGR members was nice enough to send me the other 2 I needed, These little lanterns seem to come up missing quite a bit, many of the guys are now using a small drop of glue to keep them in place on the switch.
PCRR/Dave