I'm an old Chevrolet dealer and we got the platform and stake bodies directly from the factory at least as far back as 1939, probably further back. They were mounted on the truck at the factory and weren't available in knocked down version from the factory.
I remember that in 1967, I sold a C40 to the City of Greeley, CO that was going to be used to mount a generator and lights for the Fire Department and I ordered a 12', I believe, platform body on it. It took forever to get there and, when it came in, I didn't see the transport. One of my employees told me that it was there and I told my Service Manager to go get the platform that just came in and get it serviced for delivery.
A few minutes later, he came back and said there wasn't any platform out there. Mumbling to myself that I had to do everything, I stomped out to the lot and, to my chagrin, discovered that, while I had been charged for the body on the factory invoice, they hadn't bothered to put it on the truck.
I contacted the Zone Office and they refused to believe me. I finally got them to send someone out to look at it. I asked them to let me buy an aftermarket body so I could deliver the truck, but they stalled for about two weeks and then decided to ship the body to me from the assembly plant. That took about three weeks and, when it arrived, it was completely disassembled, with all of the small parts in a box about 24 inches on a side that weighted about 200 pounds. Every nut, bolt, lock washer, staple, etc. was put loose into the box and the box split open and Chevrolet couldn't come up with an assembly drawing. It took two mechanics two days to put it together and mount it. The freight was about $400 and my warranty claim was another $400. I could have bought an aftermarket body for about $500, but I guess they were covering someone's a**.
I guess it's a little off topic, but three years later, the Fire Department brought it back to us with a bad oil leak at the rear axle pinion seal. The truck had 37 miles on it at that point. When we disassembled it we found that the pinion seal had worn a groove about 1/8" in the yoke. What we determined was that the pinion seal area was above the level of the grease in the axle and was lubricated by splash when the truck was moving. The truck was parked in the fire station and, every Saturday morning, someone pulled it out onto the ramp to wash the floor where it was parked. Then they backed it back into the bay. There was not enough speed or time to splash the lube up and forward and the dry seal wore the groove. We suggested that they drive the truck around the block every time they moved it and the problem was solved. About ten years ago, I heard that it was still in use. For what it's worth, Chevrolet paid the repair bill, even though the truck was two years out of warranty.
Maybe some of us collectors might gain something from this experience.
As a final point, I would suggest that you use marine varnish for the floor boards, not polyurethane. Polyurethane will break down from sunlight and you'll have a mess to redo. I learned this with an elaborate carved mahogany front door that got the morning sun.
Hope this wasn't too far off topic. Excuse an old goat with more memory than sense.
