and as a last resort go to
www.partsamerica.com and check them out. It was once owned by Western Auto and now is owned by Advance Auto Parts. I wanted a set of rear shocks for my 52 Panel and while Advance Auto Parts could not order them I went to Parts America and they had them. (25 bucks each) So, give them a try. They do have some older stuff from my searching around.
EDIT: I just took a look and did not see any for the rear. I did see some for the front but don't know what engine ect you have. You still may want to look for yourself.
ALSO, about a week ago I was looking around in the JCWHITNEY site and found some bushing for about half the money of others. That would be worth a try. The fellow who answered my call was nice and looked up "his suppliers" for some other stuff that I wanted but he did not have.