Dave the ignition switch assembly part # 35100-MN5-013 comes up on my fiche as a valid part ('89 GL1500). Without actually ordering one, I can't say whether Honda still stocks it though. I'd try another dealer and see what happens (or go back to the one you tried earlier) if you give him the part # to go by. Granted, that is a Canadian #, but I'd be willing to bet they are the same. I didn't try to see if the newer models list the same switch or not.
Hey, btw, welcome to the site!
Two Wheel Wing,
You're correct on that, because when I went to order the brushed aluminum trim piece for the tour box, they no longer produced it and they offered me the new chrome version. I had to order all three pieces to match.