I know of one guy in Oregon that rebuilds them. I personally haven't tried him but he seems pretty knowledgeable about rebuilding parts on these old trucks. He's connected with the Filling Station in Lebanon, Oregon. Name of Jerry Kassis. He also does videos on YouTube showing how to rebuild them if you want to try it yourself. "1947-1954 Chevrolet Pickup Door Hinge Restoration" is the YouTube to look up. This is his contact info but he won't answer his phone; leave a message;
[email protected] or call me at (541) 405-8286.