I was able to fit the headliners on my '50 COE and '37 pick up, only to have them shrink over time exposing gaps at some of the edges. The shrinkage took several months. It may be due to the low humidity in AZ so if I do it again I will buy the liner months in advance and store it in the garage.
I sure would like to know how the factory did these. I bet two people were in the cab as it came down the assembly line. I know I would be fired on day 1 if I had that job.
Kent