http://www.siriusconinc.com/search/show_result.asp try this for parts. Remember that the GL650 has the same engine, frame, suspension and such but lower rear gearing and likely heavier front fork springs. The CX500's share most external housings but little else. Transmission gears and other internals are heavier on the 650's.
The CX650E was popular in Europe, Australia, New Zealand and South Africa. The U.S. didn't get it and Canada only for 83 and 84.
Rick