I have a 55 Cameo that was built in Flint. I checked the frame back to the front cab mount,
that was as far as I could see, this is a clean, original frame, and there are no numbers stamped
anywhere on the top or the side of the frame.
I have the GM Shop Service Manual, but other than describe how to read the numbers,
it doesn't mention anything about the serial numbers being stamped on the frame.
Bob