For what it's worth...
Another source is ibmwr.org marketplace:
http://www.ibmwr.org/market/
There are currently about 50 posts in the Oilhead Parts section. Hit and miss on body panels and the like. Dealing with individuals here, so prices can vary from great to out of site.
Finally, I have also used Re Psycle:
http://www.re-psycle.com/
The owner of repsycle is normally at the spring swap meet in Winnebago,IL buying all the good parts he can find. Nice people in my experience, fair prices.
Good Luck.