My '58 has original cloth inserts panels. I'll have to take a look tomorrow but it seems to me like the fabric was attached to a chip board or card board backing and that it clips to the metal door panel. Like I said, I'll have to have a look tomorrow to be sure.
My apologies for not getting back with this info sooner. I posted the above in July and then it completely slipped my mind. I haven't been on the Bolt for a while and when I logged on I saw my own post and realized I had never followed up.
Anyway, I went out to the garage and shot a few pics. I'm not sure if the cloth on the panels is original or not but the carboard and clips are. I know the cloth has been there at least since 1964 so it might be original. We are only the second owners of the truck and I knew the original owners who were neighbors of ours. The truck needs a restoration but is pretty unmolested as far as orginality.
On the driver's side panel the clips are pulled out of the cardboard so I could pull the panel away from the door and took a few pictures. I also removed one of the clips so that I could photograph it. I bent it a little getting it out but you should be able to get the idea of the shape. Don't hesitate to post any questions. I'll try to keep an eye on this thread.
Here's the photos:
http://www.1954design.com/DoorPanelClips/IMG_1978.jpghttp://www.1954design.com/DoorPanelClips/IMG_1980.jpghttp://www.1954design.com/DoorPanelClips/IMG_1987.jpghttp://www.1954design.com/DoorPanelClips/IMG_1988.jpghttp://www.1954design.com/DoorPanelClips/IMG_1989.jpghttp://www.1954design.com/DoorPanelClips/IMG_1990.jpghttp://www.1954design.com/DoorPanelClips/IMG_1991.jpgalmost forgot, the cloth appears to be glued to the panel along the back edges and then the panel is clipped to the door.