As I said earlier, I too have wondered about the assembly process. A little while ago Brad Allen posted some old factory photos of the bed being assembled but unfortunately it was a stake body bed - not a pickup truck. I think there were some pickup beds in the back ground. It showed the beds being assembled as a separate unit which then would have been painted and then installed on the chassis. Since the bed was completely finished, it would make sense that the bolts used to attach the bed to the chassis would not have been painted. As to the bolt heads for the angle strips being painted body color, while those of the rub strips were painted black - we can only speculate as to the process.
A couple photos I took a while back of an amazing 2,700 mile, original paint 1949 GMC may give us some clues to the process. In this first photo of the underside of the bed, if you zoom in on it you can make out a number and the word "Narva" printed in grease pencil on the underside. Narva is the green color of this truck.
bed bottom The only reason I can imagine they would do this is if the bed including the bed wood was assembled separately and then painted.
In the second photo of the inside of the bed, you can clearly see that the inside of the bed top surface has been re-painted with some black looking substance.
bed top If You look closely at the bottom of the photo and zoom in on it, you can see remnants of Narva green paint on the wood along the side angle strip. This leads me to speculate that the factory may have assembled the bed wood (already assembled and finished) to the sides and then painted the bed the body color of the truck. Maybe the factory used some sort of paint mask system to minimize the over spray onto black part of the bed - but who knows?
A third photo shows the inside of the bed, with the body color bolt heads on the side angle strips, black rub strips and bolt heads and cad/natural finish cap screw heads securing the fenders to the bed sides.
bed inside Again, this was a GMC and not a Chevrolet so the process may have varied between the manufacturers and even within the plants of the same manufacturer. This is just one of those things that makes this hobby interesting.
Mike
