Check Craigslist.org, as well.
For e-Bay, you may want to create a saved, automatic search with key terms -- it will search for new entries, every day, sending you e-mail notices if anything matches your search terms. I found NOS crash bars for a 1983 bike, a couple of years ago, using this method. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII